Loma Prieta Earthquake:
Collapse of the Bay Bridge and the Cypress Viaduct
RCED-90-177: Published: Jun 19, 1990. Publicly Released: Jul 19, 1990.
- Full Report:
Pursuant to a congressional request, GAO provided information on the Loma Prieta earthquake in California, which caused sections of a highway and a bridge to collapse.
GAO found that: (1) the California Department of Transportation (CalTrans) knew that the highway's support columns were vulnerable to earthquake damage; (2) only the first phase of a three-phase seismic retrofit program had been completed for the highway; (3) CalTrans believed that the bridge had been sufficiently retrofitted prior to the earthquake and did not consider it susceptible to collapse; and (4) the Federal Highway Administration had allocated $5.5 billion to California in the last 16 years to projects that included seismic retrofitting.