An autopsy was expected to be performed on Whitney Houston today amid reports that the legendary pop singer may have drowned in the bathtub of her Beverly Hills hotel room.

TMZ reports that Houston was found yesterday afternoon by members of her entourage - including her stylist, hairdresser and two bodyguards - who became worried when she hadn't emerged from the bathroom in over an hour. Houston had been preparing to attend the annual pre-Grammy party given by her mentor, Clive Davis, the media mogul who first discovered her.

Sources tell TMZ that one of Houston's bodyguards pulled her lifeless body from the tub and performed CPR after finding her with her face underwater and her legs extended, as if she "had slid down the back of the tub." Both the bodyguard and paramedics were unable to revive her.

"Although the cause of death is unknown, it is increasingly looking like Whitney may have fallen asleep or lapsed into unconsciousness in the bathtub and drowned," TMZ reported.

TMZ has also reported that prescription drugs were found in the fourth-floor room of the Beverly Hilton Hotel and that Houston was prescribed the anti-anxiety medication Xanax, though it was not known if the singer took any pills before her death. No illegal drugs were found in the room.

Beverly Hills police Lt. Mark Rosen said there were no signs of foul play in the death of the 48-year-old singer and actress.

Houston will be honored during a special tribute at the Grammys tonight, where singers Jennifer Hudson and Chaka Kahn are set to perform. Houston, a six-time Grammy winner, presented Hudson with her first Grammy. 

Houston's chart-topping songs, a mix of rock, pop, gospel and R&B, earned her a spot in the Guinness Book of World Records as the industry's "most awarded female artist of all time." Rolling Stone magazine once called Houston "the greatest female voice of her generation."

But her very public battle with drug addiction, which marred the purity and power of her voice, and a tumultuous marriage with ex-husband Bobby Brown sent Houston spiraling out of control.

Houston was the daughter of gospel singer Cissy Houston, the cousin of 1960s pop singer Dionne Warwick and the goddaughter of Aretha Franklin. Both her mother and Warwick reportedly spoke with Houston just hours before her death and said it didn't appear that anything was wrong.