On October 17, 1989, at 5:04 p.m. PST, the Loma Prieta earthquake occurred at the Central Coast of California. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately 10 mi (16 km) northeast of Santa Cruz on a section of the San Andreas Fault System and was named for the nearby Loma Prieta in the Santa Cruz Mountains. With an magnitude of 6.9 and a maximum Modified Mercalli intensity of IX ( Violent), the shock was responsible for 63 deaths and 3,757 injuries. The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap) until two moderate occurred in June 1988 and again in August 1989.
Damage was heavy in Santa Cruz County and less so to the south in Monterey County, but effects extended well to the north into the San Francisco Bay Area, both on the San Francisco Peninsula and across the bay in Oakland. No surface faulting occurred, though many other ground failures and were present, especially in the Summit area of the Santa Cruz Mountains. Liquefaction was also a significant issue, especially in the heavily damaged Marina District of San Francisco, but its effects were also seen in the East Bay, and near the shore of Monterey Bay, where a non-destructive tsunami was also observed.
Because it happened during a national live broadcast of the 1989 World Series, the annual championship series of Major League Baseball, taking place between Bay Area teams San Francisco Giants and the Oakland Athletics, it is sometimes referred to as the " World Series earthquake", with the championship games of the year being referred to as the "Earthquake Series". Rush-hour traffic on the Bay Area freeways was much lighter than normal because the game, being played at Candlestick Park in San Francisco, was about to begin, and this may have prevented a larger loss of life, as several of the Bay Area's major transportation structures suffered catastrophic failures. The collapse of a section of the double-deck Nimitz Freeway in Oakland was the site of the largest number of casualties for the event, but the collapse of human-made structures and other related accidents contributed to casualties occurring in San Francisco, Los Gatos, and Santa Cruz.
In early 1988, the Working Group for California Earthquake Probabilities (WGCEP) made several statements regarding their forecasts for the northern San Andreas Fault segment, the San Francisco Peninsula segment, and a portion of that segment which was referred to as the southern Santa Cruz Mountains segment. The thirty year probability for one or more M7 earthquakes in the study area was given as 50%, but because of a lack of information and low confidence, a 30% probability was assigned to the Southern Santa Cruz Mountains segment. Two moderate shocks, referred to as the Lake Elsman earthquakes by the USGS, occurred in the Santa Cruz Mountains region in June 1988 and again in August 1989. Following each event, the State office of Emergency Services issued (for the first time in Bay Area history) short term advisories for a possible large earthquake, which meant there was "a slightly increased likelihood of an M6.5 event on the Santa Cruz Mountains segment of the San Andreas fault". The advisories following the two Lake Elsman events were issued in part because of the statements made by WGCEP and because they were two of the three largest shocks to occur along the 1906 earthquake's rupture zone since 1914.
The June 27, 1988, shock occurred with a maximum intensity of VI ( Strong). Its effects included broken windows in Los Gatos, and other light damage in Holy City, where increased flow was observed at a water well. Farther away from the Santa Cruz Mountains, pieces of concrete fell from a parking structure at the Sunnyvale Town Center, a two-level shopping mall in Santa Clara County. More moderate damage resulted from the August 8, 1989, shock (intensity VII, Very strong) when chimneys were toppled in Cupertino, Los Gatos, and Redwood Estates. Other damage included cracked walls and foundations and broken underground pipes. At the office of the Los Gatos City Manager, a window that was cracked had also been broken in the earlier shock. Also in Los Gatos, one man died when he fell or jumped through a window and impacted the ground five stories below.
While a Mercalli Intensity of VIII ( Severe) covered a large swath of territory relatively close to the epicenter (including the cities of Los Gatos, Santa Cruz, and Watsonville) farther to the north, portions of San Francisco were assessed at intensity IX ( Violent). At more than distant, the San Francisco Bay Area recorded peak horizontal accelerations that were as high as 0.26 g, and close to the epicenter they peaked at more than 0.6 g. In a general way, the location of aftershocks of the event delineated the extent of the faulting, which (according to seismologist Bruce Bolt) extended about in length. Because the rupture took place bilaterally, the duration of strong shaking was about half of what it would have been had it ruptured in one direction only. The duration of a typical M6.9 shock with a comparable rupture length would have been about twice as long.
The contrasting characteristics of the 1906 and 1989 events were examined by seismologists Hiroo Kanamori and Kenji Satake. The significant amount of vertical displacement in 1989 was a key aspect to consider because a long-term sequence of 1989-type events (with an 80–100-year recurrence interval) normally result in regions with high terrain, which is not seen in the Santa Cruz Mountains. Three scenarios were presented that might explain this disparity. The first is that the geometry of the San Andreas Fault goes through a transition every several thousand years. Secondly, slip type could vary from event to event. And lastly, the 1989 event did not occur on the San Andreas Fault.
When the earthquake hit, the third game of the 1989 World Series baseball championship was about to begin. Because of the unusual circumstance that both of the World Series teams (the San Francisco Giants and Oakland Athletics) were based in the affected area, many people had left work early or were staying late to participate in after work group viewings and parties. As a consequence the normally crowded freeways contained unusually light traffic. If traffic had been normal for a Tuesday rush hour, injuries and deaths would certainly have been higher. The initial media reports failed to take into account the game's effect on traffic and initially estimated the death toll at 300, a number that was corrected to 63 in the days after the earthquake.
In Santa Cruz, close to the epicenter, 40 buildings collapsed, killing six people. At the Santa Cruz Beach Boardwalk, the Plunge Building was significantly damaged. Liquefaction also caused damage in the Watsonville area. For example, sand volcanoes formed in a field near Pajaro as well as in a strawberry field. The Ford's department store in Watsonville experienced significant damage, including a crack down the front of the building. Many homes were dislodged if they were not bolted to their foundations. There were structural failures of twin bridges across Struve Slough near Watsonville. In Moss Landing, the liquefaction destroyed the causeway that carried the Moss Beach access road across a tidewater basin, damaged the approach and abutment of the bridge linking Moss Landing spit to the mainland and cracked the paved road on Paul's Island. In the Old Town historical district of the city of Salinas, unreinforced masonry buildings were partially destroyed.
Following the quake, an estimated 1.4 million people experienced power losses that were mainly due to damaged electrical substations. Many San Francisco radio and television stations were temporarily knocked off the air.
KNBR-AM (the designated station for the Bay Area's Emergency Broadcast System at the time) failed to communicate a catastrophe with the activation and instructions of the Emergency Broadcast System to the public after the quake because the engineering department at KNBR experienced major technical malfunctions and difficulties. The malfunctions during the aftermath of the earthquake caused confusion as to whether an earthquake would cause the Emergency Broadcast System to activate. KNBR began using an emergency generator, hooking up the signal from a command center right after their nearby studio was severely shaken during the quake, when most of the KNBR staff were at Candlestick for the World Series. The Mayor of San Francisco, Art Agnos, later came on the air and provided an update on the earthquake.
All four network-affiliated TV stations (KRON, KGO, KTVU and CBS affiliate KPIX-TV) would recover enough to broadcast continuous breaking news coverage of the aftermath of the quake for the next several hours, some of it picked up and broadcast nationally over their respective networks, as well as on CNN, in a manner anticipating later major catastrophes such as the 1994 Los Angeles earthquake and the 9/11 terror attacks.
Power was restored to most of San Francisco by midnight, and all but 12,000 customers had their power restored within two days.
The quake caused an estimated $6 billion (equivalent to $ billion today) in property damage, becoming one of the most expensive natural disasters in U.S. history at the time. Private donations poured into aid relief efforts and on October 26, President George H. W. Bush signed a $1.1 billion ($ billion today) earthquake relief package for California.
The Marina district was built on a Land reclamation made of a mixture of sand, dirt, rubble, waste, and other materials containing a high percentage of groundwater. Some of the fill was rubble dumped into San Francisco Bay after the 1906 San Francisco earthquake, but most was sand and debris laid down in preparation for the 1915 Panama-Pacific International Exposition, a celebration of San Francisco's ability to rebound after its catastrophe in 1906.Fradkin, 1999, pp. 138, 193–194. After the Exposition, apartment buildings were erected on the landfill. In the 1989 earthquake, the water-saturated unconsolidated mud, sand, and rubble suffered liquefaction, and the earthquake's vertical shock waves rippled the ground more severely. San Francisco Earthquake History 1915–1989. Retrieved August 29, 2009.
At the intersection of Beach and Divisadero Streets in San Francisco, a natural gas main rupture caused a major structure fire. "Earthquake". Time. Monday, October 30, 1989. Ed Magnuson. p. 1. Retrieved September 5, 2009. The San Francisco Fire Department selected civilians to help run fire hoses from a distance because the nearby hydrant system failed. Since the bay was only two blocks from the burning buildings, water from the bay was pumped by the fireboat Phoenix, to engines on the shore, and from there sprayed on the fire. Guardians of the City. Fire Department. "SFFD Fireboats: The History of the Fireboat Phoenix." Retrieved August 29, 2009. "Fireboats: Then and Now". FEMA. Technical Report Series. Special Report. USFA-TR-146/May 2003. Retrieved August 29, 2009. The apartment structures that collapsed were older buildings that included ground-floor garages, which engineers refer to as a soft story building. "Putting Down Roots in Earthquake Country". Retrieved August 29, 2009.
Immediately, a number of civilians began to free victims from the rubble of Ford's Department Store and the Santa Cruz Coffee Roasting Company – both buildings had collapsed inward on customers and employees alike. Two police officers crawled through voids in the debris, found one victim alive and another dead inside the coffee house. Santa Cruz beach lifeguards assisted in moving the victims. Police dogs were brought in to help locate other victims. A woman was found dead inside Ford's. Santa Cruz Public Libraries. Local History. Photograph Collection: rs009. The front of Ford's Department Store on the corner of Pacific Avenue and Cathcart Street. A woman inside the store died from falling debris during the earthquake. Ford's was later razed. Date: October 18, 1989. Courtesy of Ray Sherrod. Retrieved August 29, 2009. The civilians who were helpful initially, were soon viewed by police and fire officials as a hindrance to operations, with frantic coworkers and friends of a coffee house employee thought to be trapped under the rubble continuing their efforts in the dark. Santa Cruz Public Libraries. Local History. Log of Emergency Response Operations. Tuesday, October 17, 5:04 pm, 15-second earthquake! Retrieved August 29, 2009. Police arrested those who refused to stop searching. This became a political issue in the following days. sfmuseum.org. Edward J. Phipps. Overview of Fire Service Responses near the Epicenter of the Loma Prieta Earthquake Retrieved August 29, 2009. The body of a young woman coffee worker was found under a collapsed wall late the next day. "Earthquake". Time. Monday, October 30, 1989. Ed Magnuson. p. 6. Retrieved August 29, 2009.
During the first few days following the quake, electric power to most Santa Cruz County subscribers was out, and some areas had no water. Limited phone service remained online, providing a crucial link to rescue workers. Widespread search operations were organized to find possible victims inside the remains of fallen structures. As many as six teams of dogs and their handlers were at work identifying the large number of damaged buildings that held no victims.
The quake claimed one life in Watsonville: a driver who collided with panicked horses after they escaped their collapsed corral. "Earthquake". Time. Monday, October 30, 1989. Ed Magnuson. p. 2. Retrieved September 5, 2009. In other Santa Cruz and Monterey county locations such as Boulder Creek and Moss Landing, a number of structures were damaged, with some knocked off of their foundations. Many residents slept outside their homes out of concern for further damage from aftershocks, of which there were 51 with magnitudes greater than 3.0 in the following 24 hours, and 16 more the second day. The earthquake damaged several historic buildings in the Old Town district of Salinas, and some were later demolished.
Damage to the Salinas River rail bridge and subsequent repairs led to reduced traffic on the Monterey Branch Line, which contributed to the discontinuance of freight rail services in western Monterey County.
To assist with transportation during Bay Bridge repairs, Bay Area Rapid Transit ran 24-hour service in the Transbay Tube between the date of the earthquake and December 3 that same year.
Built in the late 1950s and opened to traffic in 1957 (as SR 17), the Cypress Street Viaduct, a stretch of Interstate 880, was a double-deck freeway section made of nonductile reinforced concrete that was constructed above and astride Cypress Street in Oakland. Roughly half of the land the Cypress Viaduct was built on was filled and the other half somewhat more stable alluvium.EERI, November 1989. Loma Prieta Earthquake, October 17, 1989. Preliminary Reconnaissance Report. Retrieved September 6, 2009. Because of new highway structure design guidelines – the requirement of ductile construction elements – instituted following the 1971 San Fernando earthquake, a limited degree of earthquake reinforcement was retrofitted to the Cypress Viaduct in 1977. The added elements were longitudinal restraints at transverse expansion joints in the box girder spans, but no studies were made of possible failure modes specific to the Cypress Viaduct. Caltrans has since received widespread backlash for not thoroughly studying the structure. When the earthquake hit, the shaking was amplified on the former marshland, and soil liquefaction occurred.
When the earthquake struck, the freeway buckled and twisted before the support columns failed and the upper deck fell on the lower deck. Forty-two people were crushed to death in their cars. Cars on the upper deck were tossed around violently, some of them flipped sideways, and some were left dangling at the edge of the freeway. Nearby residents and factory workers came to the rescue, climbing onto the wreckage with ladders and forklifts and pulling trapped people out of their cars from under a four-foot gap in some sections. 60 members of Oakland's Public Works Agency left the nearby city yard and joined rescue efforts.Fowler, Dave. The Initial Response to the Cypress Freeway Disaster. Retrieved September 5, 2009. Employees from Pacific Pipe drove heavy lift equipment to the scene and started using it to raise sections of fallen freeway enough to allow further rescue. Local workers continued their volunteer operation nonstop until October 21, 1989, when they were forced to pause as U.S. President George H. W. Bush and California Governor George Deukmejian viewed the damage. "People Moving Gingerly As They Pick Up Pieces". The New York Times. October 21, 1989. Retrieved August 29, 2009. That same day, survivor Buck Helm was freed from the wreckage, having spent 90 hours trapped in his car. Dubbed "Lucky Buck" by the local radio, Helm lived for another 29 days on life support, but then died of respiratory failure at the age of 58.
Although the freeway reopened in stages between 1997 and 1999, it was not fully rebuilt until 2001 so that it would comply with safety and reinforcement standards.Caltrans. 1998 Highway Congestion Monitoring Report. Retrieved September 20, 2009. In the meantime, traffic was detoured through nearby Interstate 980, causing increased congestion. Instead of rebuilding Interstate 880 over the same ground, Caltrans rerouted the freeway farther west around the outskirts of West Oakland to provide better access to the Port of Oakland and the San Francisco–Oakland Bay Bridge, and to meet community desires to keep the freeway from cutting through residential areas (at the time the original viaduct was constructed, West Oakland was predominantly occupied by African- and Hispanic-Americans). Street-level Mandela Parkway now occupies the previous roadbed of the Cypress structure.
Immediately after the earthquake, Bay Area airports were closed so officials could conduct a visual inspection and damage assessment procedures. San Jose International Airport, "Earthquake". Time. Monday, October 30, 1989. Ed Magnuson. p. 7. Retrieved September 5, 2009. Oakland International Airport and San Francisco International Airport all opened the next morning. Large cracks in Oakland's runway and taxiway reduced the usable length to two-thirds normal, and damage to the dike required quick remediation to avoid flooding the runway with water from the bay. Oakland Airport repair costs were assessed at $30 million (equivalent to $ million today).
San Francisco Municipal Railway (Muni) lost all power to electric transit systems when the quake hit, but otherwise suffered little damage and no injuries to operators or riders.Stead, William G., Muni Railway Manager. "Municipal Railway Earthquake Notebook Tuesday, October 17, 1989, 5:04 PM", December 15, 1989, letter to Art Agnos, mayor. Retrieved September 5, 2009. Cable cars and electric trains and buses were stalled in place – half of Muni's transport capability was lost for 12 hours. Muni relied on diesel buses to continue abbreviated service until electric power was restored later that night, and electric units could be inspected and readied for service on the morning of October 18. After 78 hours, 96 percent of Muni services were back in operation, including the cable cars. Amtrak intercity rail service into Oakland from the California Zephyr continued, but the Coast Starlight was temporarily suspended north of Salinas because of damage to the Southern Pacific's Coast Line.
The earthquake changed the Bay Area's automobile transportation landscape. Not only did the quake force seismic retrofitting of all Bay Area bridges,Golden Gate Bridge. Overview of Golden Gate Bridge Seismic Retrofit. Updated February 2009. Retrieved September 20, 2009.
The network put up a green ABC Sports "World Series" technical difficulties telop graphic while it scrambled to repair the video feed (the broadcast cameras and mics were powered by the local power supply), but audio from the stadium was restored after thirteen seconds via a telephone link:
Jim Palmer: Yes, yes, we hear you.
Tim McCarver: I guess...
Michaels: I don't hear a thing.
McCarver: I guess Dave Parker...
Michaels: Well, heh, I don't know if we're on the air or not, and I'm not sure I care at this particular moment but we are. Well, folks, that's the greatest open in the history of television! Bar none!
McCarver: Opened with a bang!
Michaels: Yes, it certainly did! Heh! We're still here! Heh! We are still, as we can tell, on the air, and I guess you are hearing us, even though we have no picture and no return audio, and we will be back, we hope, from San Francisco, in just a moment. ABC 1989 World Series Game 3 Earthquake – YouTube
The combined screams of excitement and panic from fans who had no idea of the devastation elsewhere could be heard in the background. "Earthquake". Time. Monday, October 30, 1989. Ed Magnuson. p. 3. Retrieved September 5, 2009. ABC then switched to episodes of Roseanne and The Wonder Years, which were on standby for a rain delay situation, while attempting to restore electricity to its remote equipment. The first television news report of the earthquake, filed by reporter Mark Coogan, came over KABC-TV in Los Angeles at 5:11 pm PDT. KGO-TV, the local owned-and-operated ABC station in San Francisco, lost power for almost 15 minutes upon the start of the earthquake, before beginning its coverage with anchor Cheryl Jennings. 10-17-1989 San Francisco Earthquake – First Minutes (KGO TV) – YouTube
With anchorman Ted Koppel in position in Washington, D.C., ABC News began continuous coverage of the quake at 5:32 pm PDT, with Al Michaels, in the process, becoming a de facto on-site reporter for ABC. CBS News also began coverage around that same time with coverage from its San Francisco affiliate KPIX-TV.Gerard, Jeremy. The New York Times, October 24, 1989. "The California Quake; NBC News Tells of Errors and Obstacles to Early Coverage of Quake". Retrieved September 11, 2009. About an hour later, NBC News also began continuous coverage with Tom Brokaw anchoring and featuring local coverage from its then-San Francisco affiliate, KRON-TV. A Goodyear Blimp had already been overhead to cover the baseball game, and ABC used it to capture images of damage to the Bay Bridge and other locations. Local Fox affiliate KTVU was knocked off the air for over 90 minutes before returning to the air with a raw feed fed from one of the station's remote trucks. KTVU anchors Dennis Richmond and Elaine Corral began their coverage from the station's parking lot, as power had not yet been restored to that section of Oakland. KTVU comes back on-air after 1989 earthquake, YouTube.
Inside Candlestick Park, fewer than half of the more than 62,000 fans had reached their seats by the time of the quake, and the load on the structure of the stadium was lower than maximum. There had also been a seismic-strengthening project previously completed on the upper deck concrete windscreen that may have prevented large numbers of injuries in the event of serious damage or even a catastrophic collapse.Lipman-Blumen, Jean. (2006) The Allure of Toxic Leaders: Why We Follow Destructive Bosses and Corrupt Politicians – and How We Can Survive Them, p. 107. Sourcebooks, Inc. Fans reported that the stadium moved in an articulated manner as the earthquake wave passed through it, that the light standards swayed by many feet, and that the concrete upper deck windscreen moved in a wave-like manner over a distance of several feet. When electrical power to the stadium was lost, someone drove a police car onto the field, where an officer used the car's public address system to advise that the game had been postponed. After the shaking subsided, many of the players on both teams immediately searched for, and gathered, family and friends from the stands before evacuating the facility.
The October 18, 1989, edition of NBC's Today that covered the earthquake ran until noon Eastern Time. Bryant Gumbel, Jane Pauley and Deborah Norville anchored from Chicago (where they had planned to originally do a special celebratory edition), with reports done by Bob Jamieson and Don Oliver in San Francisco, and George Lewis in Oakland. Jim Miklaszewski and Robert Hager covered disaster response from Washington. NBC Sports commentators Bob Costas and Jimmy Cefalo discussed the effect the temblor would have on the 1989 World Series.
The World Series was delayed while the Bay Area started the recovery process. While the teams' stadiums had suffered only minor damage, it took several days for power and transmission links at Candlestick Park to be repaired. After ten days (the longest delay in World Series history), Game 3 was held in San Francisco on October 27 and Game 4 the following afternoon as the Athletics swept the Giants, four games to none.Hinshaw, Horace. Pacifica Tribune, June 17, 2009. "Remembering World Series Earthquake." Hosted by MercuryNews.com. Retrieved August 30, 2009.
It is likely that the World Series game saved many lives, as Bay Area residents who would have normally been on the freeways were at home ready to watch the game when the earthquake hit. It is a rough estimate that thousands of people may have otherwise been on the Cypress Structure during the 5:00 pm rush-hour, as the structure was said to have carried 195,000 vehicles a day.
Sources
Foreshocks
Earthquake
Characteristics
Ground effects
Injuries and fatalities
Magnetic disturbances
Damage
Marina District
Santa Cruz and Monterey counties
San Francisco–Oakland Bay Bridge
Oakland and Interstate 880/Cypress Viaduct
Effects on transportation
Aftershocks 4.3 Oct 18 at 00:38 1989 5.2 Oct 18 at 00:41 1989 4.0 Oct 18 at 02:26 1989 4.1 Oct 18 at 03:30 1989 4.2 Oct 18 at 04:50 1989 4.2 Oct 18 at 05:18 1989 4.3 Oct 18 at 10:22 1989 4.3 Oct 19 at 9:53 1989 4.2 Oct 21 at 10:22 1989 4.7 Oct 21 at 22:14 1989 4.3 Nov 2 at 05:50 1989 4.3 Apr 18 at 13:37 1990 4.5 Apr 18 at 13:41 1990 5.4 Apr 18 at 13:53 1990 4.2 Apr 18 at 14:52 1990 4.2 Apr 18 at 15:28 1990 4.5 Mar 24 at 03:42 1991
Caltrans. Richmond – San Rafael Bridge. Retrofit Project. Retrieved September 20, 2009.
Caltrans. Bay Area Toll Bridges. Benicia–Martinez Bridge Seismic Retrofit. Retrieved September 20, 2009.
Caltrans. Bay Area Toll Bridges. Carquinez Bridge Seismic Retrofit. Retrieved September 20, 2009.
Caltrans. Bay Area Toll Bridges. San Francisco – Oakland Bay Bridge Retrofit. Retrieved September 20, 2009.
Caltrans. Bay Area Toll Bridges. San Mateo – Hayward seismic retrofit. Retrieved September 20, 2009.
Caltrans. Toll Bridge Program Oversight Committee. Toll Bridge Seismic Retrofit Report, September 30, 2008. Retrieved September 20, 2009. it caused enough damage that some parts of the region's freeway system had to be demolished. Damage to the region's transportation system was estimated at $1.8 billion (equivalent to $ billion today).USGS. Historic Earthquakes. Santa Cruz Mountains (Loma Prieta), California. Retrieved September 6, 2009.
1989 World Series and television coverage
Al Michaels: Well, heh, I don't know if we're on the air... We are in commercial, I guess.
See also
Further reading
External links
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