NEW YORK (CNN) -- Actor Heath Ledger was found dead Tuesday of a possible drug overdose in a Lower Manhattan apartment, the New York Police Department said. Heath Ledger was found dead in a Manhattan apartment. The Academy Award nominated actor was 28. "Pills were found in the vicinity of the bed," police spokesman Paul Browne told CNN. "This is being looked at as a possible overdose, but that is not confirmed yet." The pills appeared to be over-the-counter sleeping medication, said police spokeswoman Barbara Chen. Ledger was unresponsive when he was found by a housekeeper who had gone to wake him for an appointment with a masseuse in the Soho apartment, Browne said. The apartment is owned by the actress Mary-Kate Olsen, The New York Times reported. Showbiz Tonight Watch complete coverage of the sudden death of actor Heath Ledger. Tonight, 11 ET/PT on Headline News see full schedule » Ledger was declared dead at about 3:30 p.m., Browne said. In 2005, the actor played Ennis Del Mar in "Brokeback Mountain," about two cowboys who had a secret relationship. The role earned him the Oscar nomination. Ledger was born in Perth, Australia. He has a young daughter with actress Michelle Williams, his co-star in "Brokeback Mountain." Don't Miss People.com: Heath Ledger's biography I-Report: Share your photos, memories of Heath Ledger "He was just so respected in the industry," said Kim Serafin, senior editor of In Touch Weekly. "It's just horribly tragic. He was just a fine actor and a good person, so this is horribly sad and very unexpected." *SOURCE CNN*