Brittany Murphy, star of Clueless and 8 Mile, died yesterday in LA of what appeared to be natural causes, a coroner's official said.
Murphy, 32, was pronounced dead at 10.04am at Cedars-Sinai Medical Centre, hospital spokeswoman Sally Stewart said.
Murphy was transported to the hospital after the Los Angeles Fire Department responded to a call at 8am at the home she shared with her husband, British screenwriter Simon Monjack, in the Hollywood Hills.
Assistant Chief Coroner Ed Winter said Murphy apparently collapsed in the bathroom, and authorities were looking into her medical history.
An official cause of death may not be determined for some time, since toxicology tests will be required, but "it appears to be natural," Mr Winter said.
He said an autopsy was planned for Monday or Tuesday.
Mr Winter said Murphy's family was co-operating with the coroner's investigation but would not be releasing a public statement. He said funeral arrangements have not been announced.
Los Angeles police have opened an investigation into Murphy's death.
Detectives and coroner's officials were at Murphy and Monjack's home yesterday afternoon but did not talk to reporters. Paparazzi were camped outside the home, located above the Sunset Strip.
Neighbour Clare Staples said she saw firefighters working to resuscitate the actress. She said Murphy was on a stretcher and "looked as though she was dead at the scene".
Murphy's husband, wearing pyjama bottoms and no shoes, appeared "dazed" as firefighters tried to save her, Ms Staples said. "It's just tragic," she added.
Murphy's father, Angelo Bertolotti, said he learned of her death from his son, the actress's brother, and was stunned.
"She was just an absolute doll since she was born," Mr Bertolotti said from his Florida home.
"Her personality was always outward. Everybody loved her - people that made movies with her, people on a cruise - they all loved her. She was just a regular gal."
He said he hadn't heard much about the circumstances of Murphy's death. Mr Bertolotti divorced her mother when Murphy was young and hadn't seen Murphy in the past few years. He said he used to be in the Mob and served prison time on federal drug charges.
"She was just talented," Mr Bertolotti said. "And I loved her very much."
Born on November 10 1977 in Atlanta, Murphy grew up in New Jersey and later moved with her mother to Los Angeles to pursue an acting career.
Her career started in the early 1990s with small roles in television series, commercials and movies.
She is best known for parts in Girl, Interrupted, Clueless and 8 Mile.
Her on-screen work had lessened of late, but Murphy's voice gave life to numerous animated characters, including Luanne Platter on more than 200 episodes of King of the Hill and Gloria the penguin in the 2006 feature Happy Feet.
She is due to appear in Sylvester Stallone's upcoming film, The Expendables, set for release next year.
Her role in 8 Mile led to more recognition, Murphy told The Associated Press in 2003.
"That changed a lot," she said. "That was the difference between people knowing my first and last name as opposed to not."
Murphy credited her mother, Sharon, with being a key to her success.
"When I asked my mom to move to California, she sold everything and moved out here for me," Murphy said.
"I was really grateful to have grown up in an environment that was conducive to creating and didn't stifle any of that. She always believed in me."
She dated Ashton Kutcher, who co-starred with Murphy in 2003's romantic comedy Just Married.
Kutcher posted a message on Twitter yesterday morning about Murphy's death: "2day the world lost a little piece of sunshine," Kutcher wrote. "My deepest condolences go out 2 Brittany's family, her husband, & her amazing mother Sharon."