A Caltech seismologist, Dr. Lawrence Hayes, and his colleague Dr. Kim Park are at Hoover Dam to test a new earthquake prediction model when a previously unknown nearby fault ruptures and triggers a Mw 7.1 earthquake that collapses the dam. Park sacrifices himself to save a young girl and is swept away by the rushing waters. Hayes soon uncovers a chilling reality: the entire San Andreas Fault is shifting, setting off a chain reaction of massive quakes that could devastate cities along the fault line. He embarks on a desperate race to warn the population, joined by his students Alexi and Phoebe, a reporter Serena Johnson, and her cameraman Dylan, as seismic alarms multiply across the region.
In Los Angeles, a Mw 9.1 quake devastates the city and Ray Gaines, a chief rescue helicopter pilot for the Los Angeles Fire Department who is navigating a painful divorce from his wife Emma, finds himself in the thick of the crisis as he works to rescue Emma from a high-rise as the city trembles. Back in San Francisco, their daughter Blake has been visiting with Emma’s new partner Daniel Riddick, a renowned engineer, while Daniel’s firm considers Ben Taylor, a British engineer, for a big project, and Ben’s younger brother Ollie gets drawn into the escalating danger. As a second, even more powerful tremor hits, a parking garage collapses and pins Blake in Daniel’s car. Daniel abandons her in a moment of panic, though Ben and Ollie later come to the rescue, taking Blake to Chinatown and calling her parents for help.
Ray and Emma attempt to reach San Francisco by air, but a gearbox failure forces an emergency landing at a Bakersfield shopping mall. Amid chaotic crowds and looting, Ray resorts to stealing a truck to continue the journey, while Emma and Ray swap stories about their other daughter Melody, who died years earlier. The rescue mission bends toward a larger test of endurance as Blake, Ben, and Ollie strive to reach Nob Hill to signal authorities after their earlier meeting point at Coit Tower is consumed by flames.
As a colossal Mw 9.6 quake erupts, the largest earthquake in history, Ray and Emma parachute into AT&T Park just before the epic event subsides and the city sprawls into ruin. They commandeer a boat to reunite with the others, only to confront an approaching tsunami that threatens San Francisco Bay. Surviving boats and small craft push away from the surge, narrowly evading a container ship swept into the wave. The tsunami devastates the coastline as a ship smashes into the center span of the Golden Gate Bridge, trapping Daniel in the wreckage and killing him.
The enormous wave rips through the already fractured city, capsizing vessels and claiming thousands more lives. Blake, Ben, and Ollie find themselves trapped in a building—Daniel’s project—caught by the advancing flood, while it begins to crumble. In a daring rescue, Ray dives into the wreckage, frees Blake, and performs CPR to revive her as Emma drives a boat through a shattered window to pull the crew to safety. The survivors eventually regroup at a relief camp on the far side of the bay, where Ray and Emma acknowledge their renewed connection and the uncertain but hopeful future ahead.
Above the battered landscape, the remnants of the Golden Gate Bridge bear witness to the upheaval: a lone American flag slowly unfurls, symbolizing resilience and the long road to recovery. Rescue teams descend on the devastated San Francisco Bay Area as the region, once a thriving peninsula, becomes an island, and the bay now stretches from San Jose to Santa Cruz, reminding all that life after catastrophe continues, and rebuild is possible, even after a catastrophe of unprecedented scale.
