Piranha

"Operation Razorteeth," a government project involving the breeding of mutant piranhas, gets way out of hand when the fish raid a lake at a summer camp for kids. Maggie McKeown, an insurance investigator out to trace a missing teenage couple who have disappeared in the woods. With the help of a drunken recluse, Paul Grogan (Bradford Dillman), they come across a supposedly deserted army base inhabited by Dr. Robert Hoak (Kevin McCarthy) who has been breeding the deadly fish in secret. In their hunt for the missing couple McKeown and Grogan drain the army pool, unleashing millions of mutant piranhas into the lake of a nearby children's summer camp and a newly opened tourist resort.