- Directors: Alexandre Aja
- Producers: Alexandre Aja, Mark Canton
- Writers: Alexandre Aja, Patrick Melton, Marcus Dunstan, Chuck Russell
- Genres: Horror, Thriller
- Actors: Elisabeth Shue, Steven R McQueen, Adam Scott, Ving Rhames, Richard Dreyfuss, Christopher Lloyd, Jerry O Connell, Dina Meyer, Jessica Szohr, Riley Steele
The fictional Lake Victoria is the caldera of a prehistoric volcano. Each 4th of July weekend, the population of Lake Victoria, Arizona swells from 5,000 to 50,000 as young people flood the town to celebrate. When tremors tear open a crack in the lake floor, millions of piranha are released. But Sheriff Julie Forester Elizabeth Shue is seriously outnumbered, and with only one chance to save the lake and her family from totally being devoured, she must risk everything to destroy the aquatic carnivores herself.