In his first interview since his late-night Hollywood car crash in July that put him in the hospital, Shia LaBeouf tells ET's Mark Steines  that the accident was "eye opening and terrifying."  

"The car hit me at 70mph," Shia says about the crash in which his truck flipped. "It was one of the biggest things that's happened to me, for sure, in my life."

"I'm grateful to be here," he told Mark. His left hand is still in a semi-brace.   

Shia was talking with Mark to promote his new movie, 'Eagle Eye.' The 'Indiana Jones' star re-teams with his 'Disturbia' director D.J. Caruso for the high-tech film, in which he plays a man who, along with Michelle Monaghan, is forced to act as a pawn for a mysterious woman who seems to know their every move. As they get deeper and deeper into trouble, they must outwit their tormentor before her diabolical plot can be carried out.

Based on an idea by Steven Spielberg, 'Eagle Eye' also stars Rosario Dawson, Michael Chiklis and Billy Bob Thornton. The new action-thriller hits theaters September 26.

Shia's full interview will air on Monday's ET.