Skye McCole Bartusiak

Skye McCole Bartusiak, left, at Nickelodeon's 2008 Kids' Choice Awards and, right, with Mel Gibson in the 2000 movie "The Patriot." (Alberto E. Rodriguez / Getty Images and Andrew Cooper/Columbia Pictures / July 20, 2014)

Actress Skye McCole Bartusiak, best known for her role as the daughter of Mel Gibson's character in the 2000 hit movie "The Patriot," died Saturday in Texas, the Houston coroner confirmed.

She was 21. 

Bartusiak's mother, Helen Bartusiak, told the Associated Press her daughter was found unresponsive on her bed Saturday by her boyfriend. She was living in a garage apartment at her parents' home.

Helen Bartusiak said her attempts to resuscitate her daughter did not work. Her daughter, she said, had been healthy and did not drink or do drugs and the family did not yet know a cause of death.

Bartusiak appeared in a number of films and TV shows, including "The Cider House Rules," "Don't Say a Word," "House," "Lost" and "CSI."

Actress Abigail Breslin, a close friend to Bartusiak, took to Twitter to share her distress about the news.

"One of my very good friends and someone who was like a sister to me, Skye McCole Bartusiak passed away today. So devastated," Breslin tweeted.