(TMZ) -- Lindsay Lohan was in a bad car accident and is in the emergency room at an L.A. hospital... TMZ has learned.

Lindsay Lohan was driving her black Porsche on Pacific Coast Highway when it slammed into the back of an 18 wheeler.  We're told the Porsche is totaled.  The passenger window was shattered and the rear bumper was fully off her car.

Full story at TMZ.com