In Southern California, a young woman is driving around the mountains when suddenly small rocks start falling and crack the car’s windshield. Then a whole rock slide happens, causing a huge amount of stone and dirt to hit the vehicle and push it off the edge of the road. The car tumbles and spins down the hill until it falls off an edge again, but thankfully the girl survives when the car gets stuck.
However when she looks out, she discovers the car is barely hanging on some rocks. Meanwhile Ray and other members of the Los Angeles Fire Department are flying in a helicopter to search for the girl while being interviewed by a journalist about their job. When they finally see the car, they call the girl’s phone to tell her to stay calm, but she still screams when the car shakes a little.
Ray carefully flies down, tilting the helicopter to fit it through the gap. Then a rescuer goes down on a rope to secure the car, which he must do in under five minutes or the engine will fail. As soon as the guy gets closer, the girl tries to reach out, causing the car to shake again.
The car is soon secured, but unfortunately it slips and traps the rescuer. The helicopter starts shaking too and the engine won’t last much longer, so Ray decides to go down as well. As the chopper begins expelling black smoke, Ray reaches the car and tears off the door before taking the girl out.
Then the pilot cuts the rope holding the car, making the car fall and crash but also freeing the rescuer while Ray safely holds the girl. Later in the California Institute of Technology, Doctor Hayes is giving a lecture on the history of massive earthquakes, which caused lots of death and destruction around the world. Hayes also mentions the San Andreas fault, which is a meeting place of tectonic plates that runs through California.
He has no doubts that such a formation will cause a massive earthquake sooner or later. Afterward Hayes goes to his office, where Doctor Park shares news of mini-quakes detected close to the Hoover Dam and they decide to check them out. When Ray gets home, his daughter Blake calls him to ask him for a few things she left at his house that she wants to take to college.
He suddenly ends the conversation because he’s opened the mail and found the divorce papers, which leaves him very upset. Then Ray goes to Blake’s room to grab the things and finds some family pictures, which include Blake’s dead sister. At the Hoover Dam in Nevada, Park and Hayes are measuring seismic activity with a new device and are shocked to see the pulse rate suddenly make a big jump right before an earthquake hits the area.
On top of the dam, Hayes rushes to tell people to run away, but Park is inside and has to try to climb the stairs as the dam starts to crumble down and rock slides ensue. People run away in panic while the structure breaks and the water begins coming out, causing even more damage. Park hurries up and manages to come out, but at that moment he sees a girl with a hurt leg and stops to pick her up.
Then he begins running as fast as possible while the ground collapses right behind him. Suddenly Park trips and he throws the girl at Hayes before falling, only to discover his foot has been stabbed by a metal rod and he’s stuck. Hayes wants to help him, but Park tells him to stay with the girl as the dam finally collapses and a huge burst of water kills him.
Back to Ray, he receives a text from his boss telling him about the earthquake and asking him to come in. First Ray stops to drop his daughter’s things and meets with his ex-wife Emma and her boyfriend Daniel. Emma informs him she’s moving in together with Daniel, which makes Ray very upset and he awkwardly escapes by going to work.
A few hours later, Blake goes with Daniel to his workplace, and while waiting in the lobby, she befriends Ben and his little brother Ollie. Meanwhile Hayes is being interviewed by the same reporter who talked to Ray and explains that before Park died, they confirmed their new device could predict earthquakes. They’re suddenly interrupted by Hayes’ students, who have news on the activity along the San Andreas fault.
Using this information, Hayes does some calculations and traces the boundary of the fault and the dam on a map, concluding that the whole San Andreas fault will go off soon. In downtown Los Angeles, Emma is having lunch with Daniel’s sister, who asks very rude questions about the death of Emma’s other daughter. They’re interrupted when Emma gets a call from Ray, who apologizes for his attitude.
Suddenly the restaurant tables start wobbling and soon the entire building shakes as it gets hit by an earthquake. When Ray looks through the chopper’s window, he discovers the highway is crumbling down because of an earthquake as well. He asks Emma where she is and tells him to go to the roof so he can pick her up in a few minutes.
In Hayes’s office, the group rushes to hide under the tables and their device says this earthquake is a hundred times stronger. The whole San Andreas Fault is being activated and is heading toward San Francisco. Back to Blake, she gets in the car with Daniel ready to leave, when suddenly they’re reached by the earthquake too.
Daniel urges his driver to get them out of there and the car takes off as fast as possible as the entire parking lot begins collapsing and other people run around in panic. A hole opens in the ground and the car ends up going down, crashing against a wall and getting trapped by the debris. The car’s roof is pushed down by a beam and instantly kills the driver, whose seat gets bent and traps Blake’s legs.
Daniel tries to take her out to no avail, so he says he’ll go looking for help. On the first floor, Daniel finds a security guard and asks for help, but the guard is crushed by the falling ceiling. Terrified, Daniel decides to leave with the rest of the people, but Ben and Ollie overheard him talk to the guard and decide to go find Blake.
At the same time, Ray continues to fly to Los Angeles and sees the Hollywood sign going down. Fire and smoke are coming from various spots in the city, and the skyscrapers are starting to go down too. In the restaurant, people are panicking and Emma tries opening a door, only to find a hole and a man falling to his death.
The restaurant’s oven explodes and the chef catches on fire while Emma tells everyone they need to reach a roof. She finds the exit stairs and starts rushing up, but the people try to escape by going down instead. On the roof, the floor starts to collapse and Emma falls through all the debris until she painfully lands on a lower floor, which leaves her bloody and dizzy.
Refusing to give up, she starts climbing to the top of the rubble, where she’s finally found by Ray. When he tries to fly closer, something explodes and starts a fire on the roof, so Emma moves away from it and Ray hovers with the helicopter to drop a rope with a rescue basket for her. Emma runs and dodges a few holes to jump at the last second, managing to cling to the basket right before another building collapses and brings down this one in the process.
Ray immediately pulls her up and returns to the pilot seat, where he must grab the controls as the helicopter is sent into a tailspin by another falling skyscraper. After lots of spinning and losing a door, Ray gets the helicopter under control and flies away before the buildings can crush them. In San Francisco, Blake finds her phone and calls Ray to ask for help, but she soon loses the signal.
While Ray tells Emma they’re going to rescue her, more debris falls on top of the car. At that moment Ben and Ollie find Blake and try to use a metal beam to get her out, but this only makes more rubble fall. Then Ben checks the trunk and finds a tire jack which he uses to lift the fallen beam, however it only raises half a foot.
Thinking fast, Ben stabs the car’s tires to flatten them and get more room, getting Blake out right before the beam crushes the car. Meanwhile in Hayes’s office, the group analyzes the data from the monitoring systems and concludes this isn’t over. Hayes asks the reporter for help to warn people, so they run to the media center and team up with more students to hack into news broadcasts.
The reporter introduces Hayes, who informs the whole country that more earthquakes are coming. He predicts a 9. 5 earthquake or perhaps greater, and although it’s happening in California, it’ll be felt even on the East Coast.
He advises people in San Francisco to leave as fast as possible. Back to Blake’s group, the building starts to crumble so they run outside, where people are running everywhere. After lots of running, the shaking finally stops and the group goes looking for an electronics shop because Ray taught Blake to find an old model phone when the electricity isn’t working.
When they get one, Blake calls Ray and shares that Daniel abandoned her, which makes Emma furious. Ray tells Blake to get to higher ground at Coit Tower, promising to meet her there. After the call ends, Ben calls his own parents and Emma calls Daniel, only to get the voicemail and leave a threatening message for what he did.
On the streets, Daniel is walking away with other survivors when suddenly the aftershocks make another building fall. The crowd panics and runs in all directions while Daniel pushes people out of his way, causing a man to be blown away by a wave of dust. When the helicopter approaches a destroyed Bakersfield, an engine suddenly blows up.
Ray knows they’re going to crash, so he starts pulling some crazy moves, descending and going up over and over to try to land. Unfortunately the propellor hits a lamppost and the helicopter goes down, crashing right into a storefront. Thankfully Ray and Emma are fine, and they watch how people use this time of crisis to loot the mall and shoot each other like maniacs.
They sneak around the parking lot until they find a truck with its door open and Ray begins to hot wire it, only for a thief to suddenly threaten him with a gun. With no hesitation, Ray disarms him and punches him, then he leaves with Emma in the truck. Moments later on the highway, they see an elderly couple with a broken car waving their arms to make them stop.
Ray ignores them and keeps going, only to suddenly hit the brakes when Emma sees a giant gap in the middle of the road caused by San Andreas. The duo goes back to the elderly couple and Ray notices the man’s aviation hat, so the couple takes them to a nearby airport hangar. As thanks, they give the elderly couple the truck while they get on a plane.
Before taking off, Ray admits he became emotionally distant because he didn’t know how to deal with their daughter’s death and he blames himself for it because it had been his idea to go rafting that day. Ray apologizes for how he destroyed their marriage, and Emma assures him nobody could’ve saved their girl so he shouldn’t feel guilty. In San Francisco, Blake’s group is walking with the crowd that is being guided by a guard to evacuate.
Suddenly Blake sees an abandoned fire truck and pulls out an armored box of emergency supplies, which includes a radio and food rations. Ben notices the Coit Tower is surrounded by flames and smoke, so Ollie reads in his tourist book that the next highest point is Nob Hill and the trio begins heading there, which is in the opposite direction of the evacuation. Moments later the plane arrives at San Francisco, but the airport is also on fire so Ray sets the plane on autopilot and announces they’ll have to parachute out.
Emma is hesitant, so Ray straps her to his parachute and they jump together, falling for several minutes before landing safely in the middle of a baseball diamond. At that moment, another earthquake hits the area. Hayes and his team hide under the tables again, noticing the building is shaking harder this time.
In the streets of San Francisco, the trio falls as the earthquake starts bringing down the power lines and destroying buildings. The group tries to run away, but Ben falls and a shard of glass stabs his thigh. At that moment Ollie has a breakdown and Blake tries her best to comfort him.
The rest of the city continues to fall apart as buildings and even the bridge collapse, the sea is also starting to wobble. As soon as Ray and Emma come out, Ray rushes to tell people to hide behind the stadium because it’s out of the way of collapsing buildings. There’s an injured woman who can’t walk, so Ray picks her up and takes her to the stadium, where everyone huddles against the wall just in time before they can be hit by falling structures.
After making sure everyone it’s fine, Ray and Emma realize there is too much destruction to walk or drive, so they’ll have to take a boat. Once the earthquake stops, Blake takes the shard from Ben’s thigh and wraps the wound up. Hayes checks his computer and confirms it’s the biggest earthquake recorded in history.
Minutes later, Ray and Emma discover the tower is burning, but Ray knows Blake must’ve gone to another building. At that moment he notices the water level changing too quickly and realizes a tsunami is coming. A warning reaches Blake through the radio and the alarm starts echoing through the city, so they won’t make it to Nob Hill in time.
Blake notices the building that Daniel had been building nearby and decides they must hide there. On the coast, hundreds of boats are trying to get away only to be blocked by a massive wave. Some boats drive upward and fall, but Ray keeps enough control to reach the top.
Unfortunately they come across a container ship that almost kills them, thankfully Ray moves away just in time and the ship only takes their roof. Containers are also falling, so Ray drives fast to dodge them all as the ship flips over onto the Golden Gate Bridge. Lots of survivors are killed by this, including Daniel and the elderly couple.
The tsunami soon brings down the rest of the bridge and floods San Francisco, destroying what the earthquake couldn’t. Meanwhile Blake’s group is rushing upstairs and stops at the highest floor possible because the steps are blocked. Unfortunately it isn’t high enough and they see the tsunami coming for them, so they run to hide behind the pillars.
The water breaks through the window and floods the building, which starts to fall but is blocked by another skyscraper. The leaning causes some water to leak out and the trio holds onto the furniture not to fall out too. Soon Ray and Emma reach the area with the boat and notice the state of utter destruction.
Knowing Blake learned from Ray’s teachings, they head toward the tall buildings to look for her. Back to Blake and the brothers, they notice the stairs have been cleared so they go to a higher floor. While Blake checks Ben’s leg, he offers a big compliment and they kiss.
At that moment Ollie notices the boat going in the opposite direction. He and Blake start hitting the window to get their attention, but Emma and Ray can’t hear them. Then Blake remembers Ollie has a laser pointer, so she shines it at the boat’s control panel and the adults finally see them.
Suddenly another wave hits the area and breaks the windows, flooding yet another floor too. Ben and Ollie swim toward the stairs to escape, but unfortunately Blake gets caught in the water and can’t reach the brothers because of a glass door. The building is sinking, and the water levels are quickly rising.
Ray leaves the boat in Emma’s hands and kisses her before jumping into the water to swim into the building. Once inside, Ray sees Emma on the other side of the glass door and tells her to wait while he tries to move the debris. On the upper floor, Ben tells Ollie to wait safely while he goes back for Blake, but at that moment the building starts shaking again and water reaches their area as well.
This water takes the last few inches Blake had to breathe, and she soon passes out. A desperate Ray makes a final effort to move the debris and finally makes his way through to reach his daughter, taking her with him as he swims upstairs to meet with the brothers. The building continues to sink as Blake tries to give Blake CPR and Ben tries to break the windows, but he isn’t strong enough.
Outside, Emma sees this and drives the boat back to then approach the building at a very high speed, smashing her way inside. The group immediately gets on the boat and drives away, moving out of the way right before the buildings collapse behind them. Ray continues to try to resuscitate Blake and eventually gives up, but seeing Emma cry inspires him to keep trying, refusing to lose another daughter.
Suddenly Blake wakes up, dizzy but alive, and everyone hugs in relief. Sometime later, the National Guard and U. N.
relief teams arrive at the area to help the survivors. Signs, letters, and pictures are hung on a fence as a last goodbye to those who didn’t make it. Ray and his family watch what is left of the city, and he announces now it’s time to rebuild.
