'The Patriot' actress Sky McCole Bartusiak has died aged 21.

The young actress - best known for playing Mel Gibson's daughter in the 2000 movie - passed away at her home in Houston, Texas, and although the cause of death has yet to be officially determined, her mother thinks she had an epileptic seizure.

Helen McCole Bartusiak told CNN news: ''We lost our girl. We think she had a seizure and choked and nobody was there.

''They were working on her for 45 minutes and could not get a heartbeat. She was a kind and really beautiful girl.''

Child star Sky had appeared in movies including 'The Cider House Rules', 'Don't Say a Word' and 'Boogeyman' as well as landing roles on TV shows including '24', 'Lost' and 'House M.D.'

Abigail Breslin, also a child star and a close friend of Sky, paid tribute on Twitter, writing: ''One of my very good friends and someone who was like a sister to me, Skye McCole Bartusiak passed away today. So devastated.''

Roland Emmerich, who was the director and producer of 'The Patriot' also sent his condolences, writing: ''This is not the kind of news you want to begin your day with. RIP sweet Skye McCole Bartusiak.''