then, loma prieta occurred. >> pitts: geologist david schwartz is on the earthquake hazards team at the survey. he says that, as dangerous as loma prieta was, it was centered 60 miles away. >> schwartz: if people thought that was an earthquake, wait until the next one happens right here. >> pitts: when the bay area takes that direct hit from a major quake, as shown in this simulation, many of its roads, bridges and airports will be devastated. people will die. survivors will depend on a disaster route that connects to the outside world. the bay bridge will be the heart of it. >> ney: the bay bridge is built to lifeline criteria, so that... >> pitts: lifeline? >> ney: lifeline, exactly. this bridge, unlike almost every other bridge in the state, is designed to handle a very large earthquake. and then put back immediately into service for emergency services. and with a short period of time, then be open to the public for the rebuilding effort that... that will happen in this region. >> steve heminger: the replacement structure that we are designing is really state of the art. >> pitts: st