In the beautiful underwater reefs off the coast of Floridas pastoral Pajaro Island, a fissure rips open in the ocean floor. When graduate student Greg Chambers encounters the seismic readings, he rushes to tell his professor, Anthony McAlister. Greg suspects that a massive earthquake is about to give the small island a rude awakening. To make matters worse, the epicenter is right under Pajaro Islands new resort, where Anthonys estranged wife Lynn is working. As they drive to warn Lynn, the quake tears through the small town, damaging downtown and leveling several homes. The bridge connecting the island to the mainland is wiped out. Lynn and three others are trapped underground in the resorts utility tunnels. With aftershocks tearing through the site, the tunnels growing more and more unstable, and each passing minute bringing them closer to failure, the rescuers and survivors must use every resource they have to escape total disaster.