Raymond "Ray" Gaines (Dwayne Johnson) is a Los Angeles Fire Department Air Rescue pilot in the midst of a divorce from Emma (Carla Gugino) and planning a trip to San Francisco with his daughter Blake (Alexandra Daddario).
Meanwhile, Caltech seismologist Lawrence Hayes (Paul Giamatti) and his colleague Dr. Kim Park (Will Yun Lee) are at Hoover Dam doing research for a new earthquake predicting model when a nearby and heretofore unknown fault ruptures. This triggers a 7.1 magnitude earthquake that collapses the dam and kills Park.
When Ray is called into work because of this, Blake goes with her mother's new boyfriend Daniel Riddick (Ioan Gruffudd) to San Francisco, instead of Ray.
Hayes discovers that the San Andreas Fault
is shifting and will soon cause a major earthquake, thereby destroying
cities along the fault line. Emma is having lunch at a hotel in Downtown
LA with Daniel's sister Susan (Kylie Minogue)
when the fault shifts triggering a 9.1 magnitude earthquake, with Susan
among the casualties during the event. Ray saves Emma from the
collapsing building, and they barely escape the city aboard his helicopter.
In San Francisco, Daniel brings Blake to his office where she meets Ben (Hugo Johnstone-Burt), an engineering student from England seeking employment with his brother, Ollie (Art Parkinson).
Daniel and Blake leave the premises, but become trapped in their car in
the parking garage after a string of earthquakes. Daniel flees but
Blake is found by Ben and Ollie, who help her escape. They then find a
working phone and Blake calls Ray and Emma, who fly to San Francisco to
save her.
En route, Ray's helicopter fails, forcing him to make an emergency
landing at a shopping mall in Bakersfield. Amid the chaos of looting, he
steals a truck and he and Emma escape. They come across an older couple
broken down on the side of the road where the San Andreas Fault has
opened up, blocking the road and the couple, who happen to own an
airplane agree to give it up in exchange for Ray's vehicle.
In San Francisco, Blake, Ben and Ollie are trying to find a place to signal Ray, as the point they agreed to meet at, Coit Tower,
is engulfed in flames. On approach, Ray and Emma are forced to
parachute in the city when a 9.6 magnitude quake hits the city, becoming
the largest earthquake in history. Much of the city is left in ruins
and Blake, Ben and Ollie narrowly survive. Ray and Emma realizing they
cannot make their way through the destroyed city, are able to commandeer
a boat only to see that the water in the bay is beginning to recede,
indicating that a tsunami is approaching.
As it approaches, Blake, Ben, and Ollie run into Daniel's building.
The giant tsunami hits knocking over several buildings and leaving
Daniel's building flooded. Daniel is killed on the Golden Gate Bridge
when the tsunami washes in a cargo ship that severs the center span of
the bridge causing the entire roadway to snap and give way killing
thousands of others. Emma and Ray make their way through the flooded
downtown area and are finally able to locate Blake, Ben, and Ollie as
Daniel's building begins to sink beneath the water. Ray and Emma break a
window and rescue Ben and Ollie; however Blake apparently drowns. Ray
is finally able to resuscitate her and the family is happily reunited.
They head to a relief camp where the reconciled Ray and Emma talk
about their future as rescue vehicles descend on the radically altered
landscape of the San Francisco Bay Area.
