Raymond "Ray" Gaines, a Fire Department Air Rescue pilot in Los Angeles, will take his daughter Blake to San Francisco for her first semester at the university. He is divorcing his wife Emma, who has shown an interest in moving in with her affluent lover Daniel Riddick. Meanwhile, Caltech researchers Dr. Lawrence Hayes and Dr. Kim Park come to a dam to verify their seismic findings, and the dam collapses due to a powerful earthquake. Lawrence learns that the San Andreas Fault is moving, which will result in a massive earthquake in Los Angeles and San Francisco. Ray has to go to assist the dam victims, and Daniel offers to take Blake to San Francisco for a conference. Daniel invites Blake to his workplace, where she meets British architect Ben Taylor and his younger brother Ollie Taylor while waiting for him. While Ray is traveling to the dam, an earthquake strikes Los Angeles, followed by one in San Francisco. Ray and Emma hijack a boat to join the group as the earthquake subsides, only to discover a tsunami is approaching San Francisco Bay. The survivors reunite in a relief camp across the water, where Ray and Emma discuss their future. As rescue trucks descend on the significantly changed landscape of the San Francisco Bay Area, which has now stretched from San Jose to Santa Cruz, converting the San Francisco Peninsula into an island. American flag lifts up displaying what remains of Golden Gate Bridge or the city itself in all its patriotic splendor.