Chicago police have opened a death investigation after a man fatally struck a tree overnight on the North Side in the Forest Glen neighborhood.

Shortly before 3:30 a.m. Saturday, a 21-year-old man was headed north in the 6600 block of North Caldwell Avenue when he lost control of his vehicle and struck a tree, police said.

He was taken to Lutheran General Hospital in Park Ridge where he was pronounced dead.

The Major Accidents Investigation Unit was investigating the circumstances surrounding the fatal crash.