Kutcher tweeted this 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."
Her box office success was often marred by rumors about her wacky behavior on set.
In February of 2008, The New York Post reported she was making outrageous demands while acting "like a diva" on the set of "Across the Hall."
One witness said, "She's extremely difficult. When she gets to the set, it comes to a grinding halt. She's so hot and cold, you never know."
It was also reported that her husband Monjack would lurk around the set and intervene so much that producers had to call a meeting to discuss how to deal with him.
Just last month Murphy was reportedly fired from a movie she was working on in Puerto Rico. Perez Hilton reported that the actress "apparently ... has a habit of being difficult on the set," and claimed that Monjack allegedly got involved in a fight "with some locals."
Murphy's spokesperson denied reports the actress was fired from "The Caller," saying instead that she left the movie over "creative differences."
"The allegations currently circulating on the internet about Brittany Murphy and her husband Simon Monjack read like a fictional plot from one of the 50 plus movies Ms. Murphy has successfully completed without incident," her representative told World Entertainment News Network. "She was not nor has she ever been fired from any job big or small. Mr. Monjack did not engage in any alleged scuffles. Though due to creative differences Ms. Murphy and the production mutually parted ways."
Murphy's husband Monjack was rushed to a Los Angeles hospital on Nov. 29 after his plane landed. Murphy reportedly didn't think it was serious enough for Monjack to go to the hospital, but the fire department disagreed. According to TMZ, Monjack was incoherent when EMTs boarded the plane.
Despite what happened behind the scenes of her films, her colleagues respected her talent.
Director Edward Burns once told the Los Angeles Times, "She's one of those talents that is a real chameleon. She was able to be vulnerable without playing the victim -- I don't know how you do that, but she does..."