Skye McCole Bartusiak, who played Mel Gibson's young daughter in 2000's The Patriot, died at the age of 21 on Saturday, July 19. She was found at her home in Houston, Texas, but a cause of death has not been determined, CNN reports.
Bartusiak's mother Helen McCole Bartusiak told CNN that her daughter had been suffering from epileptic seizures recently, and her boyfriend found her sitting up in her bed.
"We think she had a seizure and choked and nobody was there," her mother said. "They were working on her for 45 minutes and could not get a heartbeat."
Bartusiak began her career in 1999 at the age of six in The Cider House Rules. She also played the daughter of Michael Douglas' character in 2001's Don't Say a Word.
Her mother said that more recently she had been working on producing and directing her first feature film.