A Brewer man was killed Tuesday night when he was thrown from his car after crashing into a rock wall in Plymouth.

Maine State Police say 63-year-old Michael Heath died at the scene of the crash at the I-95 off ramp to Exit 161. Troopers determined Heath, who was traveling south, failed to negotiate a curve at the Plymouth exit and his car left the road, struck a rock wall and overturned.

Heath was not wearing a seatbelt. Speed was the primary cause of the crash, police said.