LOS ANGELES - Actress Brittany Murphy, 32, died yesterday morning. Reports say she went into cardiac arrest and could not be revived.

Los Angeles police have opened an investigation into circumstances surrounding her death.

City firefighters responded yesterday morning to "a medical request" at the home of Murphy's husband, Simon Monjack. According to celebrity site TMZ, her mother found her collapsed in the shower. Paramedics found her in full cardiac arrest. Murphy was pronounced dead at Cedars-Sinai Medical Center at 10:04 a.m. West Coast time.

Police have been dispatched to Cedars-Sinai and to Murphy's West Hollywood home. The police said the inquiry was still preliminary.

Born in Atlanta, Murphy moved at age 13 to Burbank with her mother. She got her film break in Clueless (1995), in which she starred opposite Alicia Silverstone.

Murphy has made dozens of film appearances, including in Girl, Interrupted (1999), 8 Mile (2002), Sun City (2005), The Dead Girl (2006) and Across the Hall (2009). She also was featured as the voice of Luanne in the animated TV series King of the Hill. She specialized in playing characters who were troubled teenagers or mentally disturbed.

Reaction from Murphy's film peers was swift and full of shock and sadness. Jessica Simpson called her "a ray of sunshine." Ashton Kutcher, who starred with Murphy in the 2003 film Just Married, posted this message on the social-networking site Twitter: "2 day the world lost a little piece of sunshine. My deepest condolences go out 2 Brittany's family, her husband, & her amazing mother Sharon." Lindsay Lohan also tweeted: "She was a great talent w/a beautiful soul xo."

Murphy had repeatedly credited her mother, who was diagnosed with breast cancer when Murphy was 15, with being an inspiration.