Gatsby had not used his swimming pool all summer. Ironically, he decided to go for a swim at the same time George Wilson has come to his house thinking that Gatsby was driving the car that hit his wife, Myrtle. Sitting on a "pneumatic mattress" or pool float, He makes an easy target for George, who has brought a gun to kill Gatsby. Tom kills Gatsby then turns the gun on himself and "the holocaust was complete."
In the novel, "The Great Gatsby," we read about Jay Gatsby's movements following the accident that killed Myrtle Wilson. His gardener tells Jay that he is going to drain the pool for the coming winter, but Jay tells him to wait to drain the pool. He says that he will take a swim because he hasn't used the pool all summer. He decides that while he waits to hear from Daisy he will take a swim in the pool at his home. Nick takes his leave of Gatsby saying, “They’re a rotten crowd. You’re worth the whole damn bunch put together.” This is where he is killed by George Wilson who comes into his house and shoots him while he is in his pool waiting for the call from Daisy that never comes.