Twenty-eight-year-old Heath Ledger, one of Hollywood's most promising young actors, was found dead in his Manhattan apartment two hours ago, reportedly surrounded by sleeping pills. Ledger started out his career as a teen heartthrob, garnering young fans and critical derision with pap like A Knight's Tale — but like Leonardo DiCaprio and James Spader before him, Ledger quickly dropped the pretty-boy act for edgier fare that showed off his true range. His breakthrough performance as a taciturn gay cowboy in Brokeback Mountain garnered him a slew of Best Actor nominations, including a bid for the Oscar (which he lost to Philip Seymour Hoffman). Ledger had plenty of cinematic prospects ahead: his interpretation of The Joker in The Dark Knight is already the year's most buzzed-about performance, and he was slated for the lead in Terry Gilliam's next film, The Imaginarium of Doctor Parnassus. His death is a great loss for his generation of actors. (Speaking of which, between Ledger and Brad Renfro, we're starting to get seriously worried. Ryan Gosling, please tell us you're doing okay.)