A fatal explosion and sudden earthquake rock Los Angeles, and reporter John Benson seizes his chance to cover the breaking news of increasing seismic activity. His wife, Cathy, and their two kids, Brooke and Derek, arrive in the city as she works up the courage to confront John about their collapsing marriage. While John takes Derek to tour a museum, Brooke races to a party downtown, and Cathy and her sister look up to see a plume of smoke in the sky. A massive volcano violently erupts spewing lava bombs that rocket across the sky. No one is safe as the ground splits open, and the relentless lava chases the family as they race to find each other in the chaos. The news station helicopter is their only chance, but as it struggles and begins to fail, John is forced to sacrifice himself so he can save his family.