LOS ANGELES — Whitney Houston, who ruled as pop music’s queen until her majestic voice and regal image were ravaged by drug use, erratic behavior and a tumultuous marriage to singer Bobby Brown, died Saturday. She was 48.

Beverly Hills police Lt. Mark Rosen told KABC-TV that Houston died in her room on the fourth floor of the Beverly Hilton. Her body remained in the hotel, and Beverly Hills detectives were investigating.

Houston’s publicist, Kristen Foster, said Saturday that the cause of her death was unknown.

Houston’s death came on the eve of music’s biggest night — the Grammy Awards. It’s a showcase where she once reigned, and her death was sure to case a heavy pall on today’s ceremony.

Houston had been at rehearsals Thursday for a Saturday show, coaching singers Brandy and Monica, according to a person who was at the event but was not authorized to speak publicly about it. The person said Houston looked disheveled and was sweating profusely, and that liquor and cigarettes could be smelled on her breath.

Two days ago, she performed at a pre-Grammy party with singer Kelly Price.

The Rev. Al Sharpton said he would call for a national prayer this morning during a service at Second Baptist Church in Los Angeles.

“The morning of the Grammys, the world should pause and pray for the memory of a gifted songbird,” Sharpton said in a written statement.

At her peak, Houston the golden girl of the music industry. From the middle 1980s to the late 1990s, she was one of the world’s best-selling artists. She wowed audiences with effortless, powerful, and peerless vocals that were rooted in the black church but made marketable to the masses with a pop sheen.

Her success carried her beyond music to movies, where she starred in hits like “The Bodyguard” and “Waiting to Exhale.”

She had the perfect voice and the perfect image: a gorgeous singer who had sex appeal but was never overtly sexual, who maintained perfect poise.

She influenced a generation of younger singers, from Christina Aguilera to Mariah Carey, who when she first came out sounded so much like Houston that many thought it was Houston.

But by the end of her career, Houston became 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 demeanor 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 United States alone.

She seemed to be born into greatness. She was the daughter of gospel singer Cissy Houston, the cousin of 1960s pop diva Dionne Warwick and the goddaughter of Aretha Franklin.

Houston first started singing in the church as a child. In her teens, she sang backup for Chaka Khan, Jermaine Jackson and others, in addition to modeling. It was around that time when music mogul Clive Davis first heard Houston perform.

“The time that I first saw her singing in her mother’s act in a club ... it was such a stunning impact,” Davis told “Good Morning America.”

“To hear this young girl breathe such fire into this song. I mean, it really sent the proverbial tingles up my spine,” he added.

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 Oprah 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. Canceled 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.