Piranha

A restoration of Joe Dante's 1978 breakthrough film, written by John Sayles and produced by Roger Corman
An insurance investigator and her local guide search the Lost River Lake area to find too missing teenagers. When stumbling on an abandoned military facility, they accidentally release flesh-eating piranhas that were bred to use in the Vietnam war. Now the blood-thirsty piranhas are heading straight to a nearby summer resort's lake and its guests.