The Killing of Bobby Greene(1994)

Ray and his friends have come up with a great prank. They are going to kidnap a fellow high school student and hide him in an underwater cave. All is fun until the student accidentally drowns. Ray becomes obsessed with keeping the death a secret but his friends become more worried by the minute and think that they should report the death to the police. Ray will do anything he can to prevent this from happening. The bonds of friendship begin to fray and the lines of trust become blurrier by the minute building to a tragic climax.