The drowning call dropped at around 3:35 p.m. on 3200 Russell Street at Tuffly Park.
According to the mayor's office, the 16-year-old reportedly climbed the perimeter fence at the closed City of Houston facility and went down onto the water slide.
Officials say the teen remained underwater after going on the slide.
The teen was taken to Memorial Hermann Hospital, where he was pronounced dead.
ABC13 is working on gathering more details at the scene. Tune in to wherever you stream Eyewitness News for updates.