Whitney Houston, who reigned as pop music's queen until her majestic voice and regal image were ravaged by drug use, erratic behaviour and a tumultuous marriage to singer Bobby Brown, has died aged 48.
Houston died on Saturday at the Beverly Hilton Hotel in Los Angeles, where she had been staying for the past two weeks.
Kristen Foster, her publicist, said that the cause of death was unknown.
"At 3:55 pm, Whitney Houston was pronounced dead at the Beverly Hilton hotel," Mark Rosen, a police spokesman, said.
Rosen said police received an emergency call from someone in her entourage and found Houston on the floor of her room as attempts were being made to resuscitate her.
"There were no obvious signs of criminal intent at this time, and it is being investigated by the Beverly Hills police department," he said.
Al Jazeera's Rob Reynolds, reporting from Los Angeles, said that Houston had been seen at public events in good form, and had been working on post-production for the film Sparkle in recent weeks, a film which she was producing.
A coroner's official said on Sunday that the singer's body has been transported from the Beverly Hills hotel and is awaiting an autopsy.
A white coroner's van believed to be carrying Houston's body left the Beverley Hilton in the early hours of Sunday morning.
A spokesman for the Los Angeles County coroner's office said an examination had not been scheduled and that investigators are awaiting reports before an autopsy can be conducted.
"According to the celebrity website TMZ, she was seen on Thursday at a pre-Grammy party in Hollywood. Photographs were published on the web showing Whitney Houston looking quite dishevelled," said Reynolds.
"The website also says that on Friday - that would have been some 24 hours ago - Whitney Houston and members of her entourage and others were partying heavily, as they put it, at the Beverley Hilton hotel.
"Members of the hotel staff said that while there were a lot of people celebrating in advance of the Grammy’s, that this particular group stood out for its boisterousness and the loudness of its partying."
Kelley Carter, an entertainment journalist, said the news of Houston's death was all the more tragic and surprising given the star’s recent good spirits.
Carter has seen Houston shortly before her death on Saturday.
"I saw her and spoke to her and never would have thought something like this would happen just a day and a half later," Carter said.
"All of her previous problems with drug were behind her."
According to TMZ, Houston also spoke by telephone with her mother Cissy Houston and with her cousin, Dionne Warwick shortly before her death. Both of whom said that she sounded fine.
News of Houston's death came on the eve of music's biggest night - the Grammy Awards. It is a showcase where she once reigned, and her death was sure to cast a heavy pall on Sunday's ceremony.
Houston's longtime mentor Clive Davis was to hold his annual concert and dinner on Saturday; it was unclear if it was going to go forward.
By the end of her career, Houston had become a stunning cautionary tale of the toll of drug use.
Her album sales plummeted and the hits stopped coming; her once serene image was shattered by a wild demeanour and bizarre public appearances.
She confessed to abusing cocaine, marijuana and pills, and her once pristine voice became raspy and hoarse, unable to hit the high notes as she had during her prime.
"The biggest devil is me. I'm either my best friend or my worst enemy," Houston told ABC's Diane Sawyer in an infamous 2002 interview with then-husband Brown by her side.
It was a tragic fall for a superstar who was one of the top-selling artists in pop music history, with more than 55 million records sold in the US alone.
Houston staged what seemed to be a successful comeback with the 2009 album I Look To You. The album debuted on the top of the charts, and would eventually go platinum.
Things soon fell apart. A concert to promote the album on Good Morning America went awry as Houston's voice sounded ragged and off-key. She blamed an interview with Winfrey for straining her voice.
A world tour launched overseas, however, only confirmed suspicions that Houston had lost her treasured gift, as she failed to hit notes and left many fans unimpressed; some walked out.
Cancelled concert dates raised speculation that she may have been abusing drugs, but she denied those claims and said she was in great shape, blaming illness for cancellations.