Jones is cast as the head of the Los Angeles County Office of Emergency Management (LAC OEM) which has complete authority in the event of an emergency or natural disaster. His character attempts to divert the path of a dangerous lava flow through the streets of Los Angeles following the formation of a volcano at the La Brea Tar Pits.
A joint collective effort to commit to the film's production was made by the film studios of 20th Century Fox, Moritz Original and Shuler Donner/Donner Productions. It was commercially distributed by 20th Century Fox. Volcano explores civil viewpoints, such as awareness, evacuation and crisis prevention. Although the film used extensive special effects, it failed to receive any award nominations from mainstream motion picture organizations for its production merits.
Volcano premiered in theaters nationwide in the United States on April 25, 1997 grossing $49,323,468 in domestic ticket receipts, on a $90 million budget. It earned an additional $73.5 million in business through international release to top out at a combined $122,823,468 in gross revenue. Despite its release and recognition, Dante's Peak (which was released 2 months before) gained more commercial success than Volcano. It was also met with mixed critical reviews before its initial screening in cinemas. The Region 1 code widescreen edition of the film featuring special features was released on DVD in the United States on March 9, 1999.
In Los Angeles, an earthquake strikes. Michael Roark, the director of the city's Office of Emergency Management, insists on coming to work to help out with the crisis, even though he has taken a vacation with his daughter Kelly. His associate, Emmit Reese, notes that the quake caused no major damage, but seven utility workers are later burned to death in a storm drain at MacArthur Park; one escapes and survives but is severely burned on one side of his face. As a precaution, Roark tries to halt the subway lines which run parallel to where the deaths took place, but Los Angeles MTA Chairman Stan Olber opposes, feeling there is no threat to the trains. Against regulations, Roark and Gator Harris venture down the storm sewer in the park to investigate. They are nearly burned alive and barely escape with their lives when hot gases suddenly spew out of a crack in the concrete lining and floods the tunnel. Geologist Dr. Amy Barnes believes that an underground volcano may be rapidly forming beneath the city with magma flowing underground (similar to the formation of the Mexican volcano Parícutin which emerged and grew tremendously in just one week.) Unfortunately, she has insufficient evidence to make Roark take action.
The next morning, at around 5:15 A.M., Barnes and her assistant Rachel venture in the storm sewer to investigate the scene of the incident, where they discover the crack in the ground which released the gases earlier. While they are taking samples, a more powerful earthquake strikes and Rachel is killed when she falls into the crack that is engulfed by a rush of the hot gases. Near the La Brea Tar Pits, smoke rises out along with lava bombs which ignites several buildings. Steam explodes from the sewer system, while a subway train derails underground, trapping the passengers inside and exposing them to the severe heat and toxic gases, which causes them all to eventually pass out.
Roark helps injured firefighters out of the area. Moments later, a newly formed volcano erupts from the tar pits and lava begins to flow freely down Wilshire Boulevard, incinerating everything in its path, including Roark's GMC Suburban and an LAFD fire truck downed by a lava bomb, killing two firefighters who are trapped inside. Roark and his daughter become separated as she is injured when a nearby lava bomb sputters and burns her leg, and she is taken to Cedars-Sinai Medical Center by Dr. Jaye Calder. Meanwhile, Olber leads his team through the Red Line tunnel to the derailed train to look for survivors. They manage to save everyone, but Olber notices that the train driver is still missing and goes back; he finds the driver still alive but unconscious, just as the lava reaches the train and begins to flow underneath it. Melting the floors, the aluminum and the steel train itself. Olber sacrifices his life to save the driver by jumping into the lava flow, throwing the driver to safety as he burns to death. Roark, Barnes, and police lieutenant Ed Fox devise a plan to stack concrete barriers at the intersection of Wilshire Boulevard and Fairfax Avenue, creating a cul-de-sac to pool the lava as helicopters dump water on it to form a crust, making the operation a success but Barnes notices that the volume of ash falling is too intensifying for the eruption to be over. She later theorizes that the magma is still flowing underground through the Red Line subway extension, and calculates that the main eruption will occur at the end of the line at the Beverly Center near Cedars-Sinai. To prove this, Dr. Barnes and Roark lower a video camera into the tunnel to watch it, only for the camera to be incinerated by a fast-moving flow of lava. They calculate the speed and realize that they have thirty minutes until the lava hits the end of the Red Line.
Through Roark's direction, explosives are used to create channels in the street to divert the flow of lava into Ballona Creek, which will later flow into the Pacific Ocean, but Barnes realizes that the street is sloping in the opposite direction and instead of going in to the creek the lava would flow right into the direction of the injured patients much to the displeasure of Roark and Fox, knowing that there's over 2,000 patients and saving every one of them would be impossible. Just when all hope appears lost, Roark engineers another plan to demolish a 22-story condominium building (which is currently under construction by Jaye's husband) to block the lava's path from flowing towards the patients and the rest of the Los Angeles West Side. Gator refuses to abandon an LAPD SWAT cop who has gotten trapped under a core column while slotting explosive charges just as the lava reaches the dead end of the Subway tunnel extension and explodes out of the ground in a massive geyser; he sacrifices their lives to detonate the final explosive charge. Roark then spots Kelly nearby, trying to retrieve a small boy who wandered off, putting them in the path of the collapsing building. Roark barely manages to save both of them from being crushed as the building collapses. The plan is successful and the lava flows safely to the ocean. Roark escapes from the wreckage with Kelly and the young child. The death toll is nearly a hundred people, thousands injured and damages in the billions. It starts to rain, with surviving civilians having a sign a relief. Reese shows up with the family dog Max, along with a call from the Chief of the Los Angeles Police Department on how to rebuild the city. Roark tells Reese he's on vacation and to tell the chief that too as he goes home with Kelly while Reese takes over to handle the situation. The film ends with an epilogue displaying a graphic stating that the volcano, named "Mount Wilshire", is still in an active state.