Whitney Houston death: Bathtub drowning among scenarios probed Investigators probing the death of Whitney Houston are trying to determine whether she drowned while in a bathtub at the Beverly Hilton on Saturday shortly before she was set to attend a pre-Grammy Awards gala, according to a source who has been briefed about the case. The source, who spoke to the Los Angeles Times on the condition of anonymity because the case was ongoing, stressed investigators still have many unanswered questions, particularly about what Houston was doing in the hours before her death. Investigators are also interviewing family members and friends to determine whether Houston had any underlying medical conditions, a practice common in death investigations. The Los Angeles County coroner's office is expected to perform an autopsy Sunday, but it's likely that a final cause of death will be deferred until toxicology test results come in. The source said drowning is one of several scenarios that investigators are examining as they gather evidence. Beverly Hills police said there was no indication of foul play in Houston's death but also said it was premature to say that she had died of natural causes. Houston had drug and alcohol problems for years, and last May her spokeswoman said she was going back into rehab. PHOTOS: Stars react The Times reported that days before her death Houston had been acting strangely, skipping around a ballroom and reportedly doing handstands near the hotel pool. According to The Times' Gerrick D. Kennedy, Houston greeted people with a warm smile but appeared disheveled in mismatched clothes and hair that was dripping wet. Police said that so far they do not have evidence that drugs played a role in Houston's death. After news of her passing, fans flocked to the hotel, some leaving flowers and tributes. On Sunday morning, a bleary-eyed Ray J was briefly inside the lobby of the Beverly Hilton surrounded by three companions. The musical artist, who reportedly had been dating Houston on and off, had his hood on, and 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. A little later, Ray J left the hotel in the passenger seat of a red Ferrari. Fans have begun assembling a makeshift memorial of flowers, candles and notes for Whitney Houston outside the Beverly Hilton. "Bittersweet memories that is all we will take us," read one note. We will always LOVE you. One woman drove by, turning onto Santa Monica Boulevard from Wilshire Boulevard, asking a reporter on the street corner to add a bouquet to the mix. Another woman snapped a photo with her iPhone on the way to the bus stop. "Oh there's my bus, I'm always late," she said, running to the stop. Just hope I'm not late to heaven. Worshipers at the First A.M.E. Church of Los Angeles held a special moment of silence in honor of Houston at their 10 a.m. service. Their pastor John J. Hunter described Houston as "one of the most dynamic voices of our time," according to an announcement on the church website. "We are all deeply saddened by her passing and our hearts go out to her family," he said. An outdoor candlelight memorial and public gathering is scheduled to begin at 5 p.m. Monday in Leimert Park and will continue for at least two hours, according to community organizer Najee Ali. Fans will be able to express their grief and their admiration of Houston's talents while Houston's recordings play throughout the evening, he added.