Murphy was pronounced dead at 10:04 AM at Cedars-Sinai Medical Center, hospital spokeswoman Sally Stewart said, according to AP. She was transported to the hospital after collapsing in the bathroom. An investigation into the cause of her death is ongoing.

Born Nov. 10, 1977, in Atlanta, Murphy rose to prominence as one of the young stars of the seminal 1995 teen film "Clueless." In Amy Heckerling's updating of Jane Austen's "Emma," she played Tai, an awkward new kid in a ritzy California school who is socially adopted by popular girl Cher, played by Alicia Silverstone.

She went on at appear in "Girl, Interrupted" (1999), "Don't Say a Word" (2001), "Just Married" and "8 Mile" (both 2002). In more recent years, as her film opportunities shrank, she tried her hand at music, finding some success singing on the 2006 Paul Oakenfold single "Faster Kill Pussycat," which became a club hit, and hit number seven in the UK singles chart. She is also well known to television views as the voice of the dimly coquettish Luanne Platter on Fox's "King of the Hill."

Her sole foray into Broadway was memorable. In 1997, shortly after her success in "Clueless," she starred as Katie, the object of longshoreman Anthony LaPaglia's unknowing lust in a Roundabout Theatre Company revival of Arthur Miller's A View From the Bridge. In the role, the petite Ms. Murphy (she was 5'1") put her whiskey-voiced, natural girlish sensuality to good use. The New York Times' Vincent Canby called her "exceptional."

In May 2007, Murphy married British screenwriter Simon Monjack in a private Jewish ceremony. Mr. Monjack survived her.

Ms. Murphy grew up in New Jersey and later moved with her mother to Los Angeles to pursue acting. When her parents divorced, she changed her name from Bertolotti to her mother's maiden name, Murphy. She began appearing on television while still a teen.

Ms. Murphy acted in four films that are expected to by released in 2010, included "The Expendables," directed by and starring Sylvester Stallone.