Bobby Driscoll, the voice of Peter Pan and another of Walt's early big child stars.
Dead at 31 from drugs. He started drugs at 17.
It was alleged his is one of many molested child stars, but there's no evidence to corroborate (other than his self-destructive behavior with drugs). And dead men tell no tales.
Of course, they waited until the re-release of one of his films to announce that he was dead. Wouldn't wanna hurt that box office.