Just 21 years after she wowed the audience with this best-ever performance of the American national anthem, the Star-Spangled Banner, at the Super Bowl of 1991, Whitney Houston is dead at the age of 48.

The superstar was found unresponsive in her room at the Beverly Hilton in Hollywood at 4p.m. yesterday on the eve of the Grammies.

There was no immediate word on the cause of her death, but the authorities said there were no signs of foul play.

On Thursday afternoon at the hotel, Houston was behaving erratically , dripping sweat and in dishevelled clothes. She had been disruptive at rehearsals for music mogul Clive Davis' annual Grammy industry party.

The party at the Hilton on Saturday night was to include a performance by Houston.

The party went on. Davis told his guests that he had a "heavy heart" and was "personally devastated" by the star's death, "but Whitney would have wanted the music to go on, and her family has asked for us to carry on."

The star's professional decline had become a familiar part of her public saga, said the Los Angeles Times. "Her haggard appearance at times shocked fans who had once been drawn to the singer's world-class smile and approachable glamour ."

Many fans pointed to her relationship and 14-year marriage with Bobby Brown as "the axis on which her life seemed to be spinning so madly," said the paper. "She acknowledged that she was immersed in drugs, and the toll on her voice and her appearance was difficult to watch."

"The biggest devil is me," the singer told ABC's Diane Sawyer in a notorious 2002 interview. "I'm either my best friend or my worst enemy."