Ms. Houston's longtime mentor, Clive Davis, was to hold his annual concert and dinner Saturday, and a representative of the show said it would proceed. Ms. Houston was supposed to have appeared at the gala.
Ms. 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 that Ms. Houston looked disheveled, was sweating profusely, and smelled of liquor and cigarettes.
Rosen said police received a 911 call from hotel security about Ms. Houston at 3:43 p.m. local time Saturday. Paramedics, already at the hotel because of a Grammy party, unsuccessfully tried to resuscitate her, the lieutenant said.
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.
At her peak, Ms. Houston was the golden girl of the music industry. From the mid-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 church.
Her success carried her beyond music to movies, where she starred in hits such as The Bodyguard and Waiting to Exhale.
She had the perfect voice and the perfect image: a gorgeous singer who maintained perfect poise.
She influenced a generation of younger singers, including Christina Aguilera and Mariah Carey, who when she first came out sounded so much like Ms. Houston that many thought it was Ms. Houston.
