John Corbett stars as Matt Andrews, a geologist who is asked to investigate why there have been two large sinkholes affecting the city of New Orleans.
Jessica Steen plays Corbett's girlfriend Allison Beauchamp, assistant to the Mayor, who has to decide whether the problems with the sinkholes will spread far enough to require that the remainder of Mardi Gras be cancelled, which would be a complete economic disaster to the city.
The only answer is to obtain several tons of polyurethane liquid in 2 compounds which when combined produces an expanding foam that will fill the huge sinkhole cavern.
Due to an emergency, while Matt is underground inspecting the caverns, he becomes partially trapped, and has to ask to have the foam started (which will kill him if he can't find an escape) because if they don't start the flow of the liquid immediately, the ground underneath downtown New Orleans will collapse similar to the effects of soil liquefaction and thousands to tens of thousands of people will be injured or killed.
Matt points out the sinkholes, if they do fail and open up, could be as serious a disaster to the city as if its levees collapsed, an event that did happen as a result of Hurricane Katrina in 2005.