Her publicist, Kristen Foster, confirmed the singer's death Saturday only hours before Houston was due to perform at music mogul Clive Davis's annual pre-Grammy party at the Beverly Hilton Hotel.
"I can confirm that Whitney Houston was pronounced dead at 3:55 p.m. at the Beverly Hilton Hotel. We received a call at 3:43 p.m. from hotel security and Beverly Hills fire and police responded minutes later," Beverly Hills Police Lieutenant Mark Rosen tells PEOPLE.
"Someone in her entourage found her unresponsive in her room ... It's unclear who notified hotel staff because she has quite an entourage here at the hotel. We attempted to resuscitate her, to no avail."
As to whether there was any evidence of drugs or foul play, Rosen responded: "At this time, there's no obvious evidence of foul play or cause of death."
Earlier this week, the six-time Grammy winner, whose record sales in the United States alone totaled 55 million, was spotted having a night out on the town in L.A. at "Kelly Price & Friends Unplugged: For The Love Of R&B Grammy Party" at Tru Hollywood.
With Houston was her 18-year-old daughter, Bobbi Kristina, who was the product of Houston's troubled marriage to soul crooner Bobby Brown. The two wed in 1992, and the following year Brown was charged with domestic abuse. After several rocky years together, the couple divorced in 2007.
The Glory DaysBorn in Newark, N.J., the daughter of gospel singer Cissy Houston, the cousin of '60s pop diva Dionne Warwick (and the late Dee Dee Warwick) and the goddaughter of Aretha Franklin first started singing in the church as a child. In her teens, Whitney sang backup for Chaka Khan, Jermaine Jackson and others, in addition to modeling.
Around the same time, she joined her mother singing in New York City nightclubs, which helped her catch the ear of Clive Davis. Houston's debut album, Whitney Houston, was produced by Davis and released in 1985, selling millions of copies. Among the hits off of it were "Saving All My Love for You," "How Will I Know," ''You Give Good Love" and "The Greatest Love of All."
Two years later, songs like "I Wanna Dance With Somebody" and "Where Do Broken Hearts Go," both topped the charts, and by 1992 she rose to the ranks of Hollywood stardom opposite Kevin Costner in the runaway hit The Bodyguard.
Her StrugglesBut Houston's considerable talent was often overshadowed by her struggles with addiction and her widely chronicled marriage to her bad-boy husband.
In 2010, Houston opened up about the darker side of her life, admitting to Oprah Winfrey that by the time she was working with Denzel Washington on The Preacher's Wife in 1996, drugs were a routine part of her life. She went to rehab twice before getting clean, she told Winfrey.
In May 2011, her rep said Houston was once again receiving help for drug and alcohol abuse.
The status of her health in recent weeks had been open to discussion, though she appeared to be on a comeback trail as far as the movies were concerned. After a more than 15-year hiatus from the big screen, Houston recently filmed Sparkle, due to arrive in theaters Aug. 10, with Jordin Sparks.
With reporting by KEN LEE