Officials trying to determine whether Houston drowned in bathtub

When paramedics arrived at Whitney Houston's hotel suite in Beverly Hills, they found her unresponsive in the bathtub, and officials said that drowning is one of the possible causes of death being investigated.

The Los Angeles County coroner's office said it performed an autopsy on the singer's body Sunday, but deferred any conclusion about her death until toxicology results are available, in six to eight weeks.

Sources who were briefed on the probe Sunday said drowning is one of several scenarios investigators are exploring. The sources stressed that authorities still have many unanswered questions, particularly about what Houston was doing in the hours before her death. They are also interviewing friends and family members to determine whether Houston had any underlying medical conditions, said the sources, who spoke to The Times on the condition of anonymity because the case was ongoing.

Photos: Whitney Houston | 1963-2012

One source with knowledge of the case said that although Houston was found in the bathtub, officials are still unsure whether she died of natural causes or was in some other way stricken.

Houston struggled with drug and alcohol problems for years, and last May her spokeswoman said the singer was going back into rehab.

Houston was in Beverly Hills for music industry titan Clive Davis' annual pre-Grammy party Saturday night at the Beverly Hilton. Over the last few days, she had made several public appearances. At times she had been acting strangely, skipping around a ballroom and reportedly doing handstands near the hotel pool. Houston greeted people with a warm smile but at times appeared disheveled in mismatched clothes and hair that was dripping wet.

On Thursday, Houston dropped by the rehearsals for the event, where journalists — including a Times reporter — were in attendance. A Grammy staffer said that as reporters interviewed Davis and singers Brandy and Monica, Houston was dancing just off camera to make the singers and Davis laugh. Grammy personnel expressed concern that she would be caught on camera, and that reporters would write about her behavior.

Beverly Hills police officials, who are investigating the case in conjunction with the coroner's office, said Saturday night that it is far too early to determine whether drugs or alcohol played any role in Houston's death. Police said there is no indication of foul play but placed a security hold on her coroner's office file, which is common in high-profile cases.

Lt. Mark Rosen said Houston was at the hotel with a large entourage of family, friends and co-workers, some of whom helped identify her body after she was declared dead.

On Sunday morning, bleary-eyed music star Ray J was seen surrounded by three companions in the hotel's lobby.

Ray J, who reportedly had been dating Houston on and off was being consoled by others.

"Whitney dead," he repeated multiple times as one friend grabbed him by the shoulders. "Whitney dead. We all gotta live with that."

Later, Ray J left the hotel and was whisked away in the passenger seat of a red Ferrari.

Full coverage: Whitney Houston | 1963-2012

A short time later, Houston's daughter, Bobbi Kristina Brown, was rushed by ambulance from the hotel to nearby Cedars-Sinai Medical Center, police said. Details of her medical problem were not available, but she was reportedly released from the hospital a few hours later.

The hotel has also been besieged by fans who assembled a makeshift memorial of flowers, candles and notes for Houston.

"Bittersweet memories that is all we will take with us," read one note. "We will always LOVE you."

One woman drove onto Santa Monica Boulevard from Wilshire Boulevard, asking a reporter on the corner to add a bouquet to the mix. Another woman snapped a photo with her iPhone on the way to the bus stop.