Oscar-nominated actor Heath Ledger, who gained critical acclaim in 2005’s Brokeback Mountain, was found dead in a Manhattan apartment, CNN.com reports.  He was 28.

No cause of death has been released by New York City police.  The New York Fire Department received a call just before 2:30 p.m. about a “cardiac arrest” emergency.

Ledger grew to stardom in the 1990s, particularly in his homeland, Australia.  He gained critical acclaim for a small role in 2001’s Moster’s Ball.  Other credits include A Knight’s Tale, The Order and Lords of Dogtown.

He earned his Oscar nomination in 2005 starring opposite Jake Gyllenhaal in Brokeback Mountain, a story of two cowboyws having a secret relationship.  It was on the set of that movie where he met fiancée Michelle Williams.  Together, they have a daughter, Matilda Rose Ledger, born Oct. 28, 2005.  Gyllenhaal is Matilda’s godfather.

Most recently, Ledger starred in I’m Not There, an account of Bob Dylan’s life.  According to IMDb.com, he is set to star in The Dark Knight, premiering later this year.