Police have closed their investigation into Whitney Houston's death without finding any evidence to suggest it was anything than an accidental drowning, investigators announced Wednesday.

The Beverly Hills Police Department did not release a detailed report on the case, but Lt. Mark Rosen said the conclusion came after detectives reviewed the complete findings of the coroner's office. Coroner's officials ruled Houston drowned accidentally at the Beverly Hilton on Feb. 11 and that heart disease and cocaine use contributed to her death.

Beverly Hills authorities also released a minute-long 911 call made by a hotel worker who summoned police and paramedics to Houston's suite at the hotel. The call revealed few details, other than that people in the Grammy-winning singer's room repeatedly hung up on hotel personnel after discovering Houston in a bathtub.

The dispatcher had asked to be patched into the room to deliver lifesaving instructions, but the security worker said that wasn't possible. He said a woman who notified the hotel that Houston was unresponsive was "irate" and didn't provide many details.

Rosen re-iterated condolences to Houston's family and friends in a brief statement.

Houston's death on the eve of the Grammy Awards stunned the world. The singer had been attempting a comeback and had finished work on a remake of the film Sparkle when she drowned.

Toxicology results showed cocaine throughout her body, and coroner's officials said the results indicated chronic use. In the bathroom, investigators found a small spoon described by investigators as having a "crystal-like substance" in it, and they discovered a white powdery substance in a drawer, a coroner's report released last week showed.

Houston had a history of drug abuse which marred her career, robbing her of her voice and reputation, but family and friends described her as intent on returning to glory in the months before her death. Her unexpected death at age 48 sparked a renewed interest in her music and movies, sales of which will benefit her only daughter, Bobbi Kristina.