Updated Feb. 12, 2012, 1:56 AM ET
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 reporters outside the Beverly Hilton that Houston was pronounced dead at 3:55 p.m. in her room on the fourth floor of the hotel. Her body remained there and Beverly Hills detectives were investigating.
"There were no obvious signs of any criminal intent at this time," Rosen said.
Houston's publicist, Kristen Foster, said Saturday that the cause of her death was unknown.
Rosen said police received a 911 call from hotel security about Houston at 3:43 p.m. Saturday. Paramedics who were already at the hotel because of a Grammy party unsuccessfully tried to resuscitate the singer, he said.
Beverly Hills Police Department later issued a statement:""Whitney Houston was pronounced dead that the scene by members of her entourage which included friends, co-workers, and family. Ms. Houston's daughter and mother were notified of here death."
The statement also added that "the investigation is currently being conducted" and that "there is no additional information at this time."
"The actual cause of death will be determined by the L.A. Co. Coroner's Office," it said.
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 cast a heavy pall on Sunday's ceremony.
Her longtime mentor Clive Davis was to hold his annual concert and dinner Saturday, and a representative of the show said it would proceed.
Houston was supposed to appear at the gala, and Davis had told The Associated Press that she would perhaps perform: "It's her favorite night of the year ... (so) who knows by the end of the evening," he said.
Producer Jimmy Jam, who had worked with Houston, said he anticipated the evening would become a tribute to her, and he expected there to be one at the Grammys as well.
Houston had been at rehearsals for the show Thursday, 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, was sweating profusely and liquor and cigarettes could be smelled on her breath.
Two days ago, she performed at a pre-Grammy party with singer Kelly Price. Singer Kenny Lattimore hosted the event, and said Houston sang the gospel classic "Jesus Loves Me" with Price, her voice registering softly, not with the same power it had at its height.
Lattimore said Houston was gregarious and was in a good mood, surrounded by friends and family, including daughter Bobbi Kristina.
"She just seemed like she was having a great night that night," said Lattimore, who said he was in shock over her death.
"I just can't talk about it now," Houston's godmother, Aretha Franklin, said in a short statement. "It's so stunning and unbelievable. I couldn't believe what I was reading coming across the TV screen."
The Rev. Al Sharpton said he would call for a national prayer Sunday 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.
In a statement, Recording Academy President and CEO Neil Portnow said Houston "was one of the world's greatest pop singers of all time who leaves behind a robust musical soundtrack spanning the past three decades."
"Her powerful voice graced many memorable and award-winning songs," Portnow said. "A light has been dimmed in our music community today, and we extend our deepest condolences to her family, friends, fans and all who have been touched by her beautiful voice."
CBS News has learned that singer Jennifer Hudson will do a tribute to Houston by singing her songs during the Grammys.
At her peak, Houston was 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 palatable 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.