The Piranhas, as known in the Piranha series of films, are a School of ravenous, bloodthirsty, and prodigious genetically engineered breed of piranhas that were created as a bio-weapon for the use of the U.S. Military during the era of the Cold War.
During the Vietnam War, the U.S. Military gave an order to develop an effective bio-weapon project codenamed Operation: Razorteeth, which was tasked with engineering a breed of piranhas that could endure the cold water of the North Vietnamese rivers and inhibit Viet Cong movement. The project was shut down when the war ended and the specimens were due to be eradicated via poisoning, but some of the mutant specimens survived the poisoning protocols, one of the project's researchers Dr. Robert Hoak tended to them to salvage his work at the abandoned Military research installation.
Lost River Lake IncidentEdit
Several years later, two teenagers exploring at night come upon the abandoned military installation. They take advantage of what they thought to be a swimming pool to skinny dip. The teenagers are devoured by the piranhas inhabiting the pool and disappear under the water.
Investigator Maggie McKeown is dispatched to find the missing teenagers near Lost River Lake. She hires surly backwoods drunkard Paul Grogan to serve as her guide. They come upon the abandoned compound, which functioned as a fish hatchery prior to being militarized. Unfortunately during their investigation at the facility , they unknowingly unleashed the piranhas into the river where they proceed in devouring everything in their way. Hoak agrees to help Maggie and Grogan to stop the piranhas from reaching into public, however he was killed by the School of the carnivorous fish in an attempt to save a boy, Grogan stops the dam attendant from opening the spillway and calls the military. The military soon arrives under the leadership of Colonel Waxman and former Razorteeth researcher Dr. Mengers and feed poison into the upstream section, ignoring the protests that the fish survived the first attempt. When Grogan discovers that a tributary bypasses the dam, Waxman and Mengers quarantine them to prevent the agitated pair from alerting the media. When they escape, Waxman alerts law enforcement to capture them. The School attacks the summer camp during a swimming marathon, injuring many and killing two.
The School continues downriver. Waxman and Mengers arrive at the water park to intercept Grogan and Maggie, but the piranha attack the resort, killing many, including Waxman. Grogan and Maggie commandeer a speedboat and rush to the shuttered smelting plant at the narrowest point of the river. Remembering the empty facility pond, Grogan realizes the fish can survive in salt water; if the School passes the delta, they will reach the ocean and spread over the entire world. He intends to open the smelting refuse tanks, hoping that the industrial waste will kill the fish. They arrive at the plant ahead of the fish, but the elevated water level has submerged the control office, and Grogan must go underwater Grogan struggles to move the rusted valve wheel when The School arrives and attacks him. The assault hyperadrenalizes him, and he manages to open the valves just as Maggie guns the engine and pulls him to safety. The piranhas were believed to have been killed by the industrial waste, but the piranha's characteristic trilling sound drowns out the waves on a beach, indicating that the fish have made it to the ocean.