A young man was killed Sunday after a vehicle crashed into a tree in south suburban Flossmoor.

The 23-year-old was in a vehicle about 3:30 a.m. when it crashed in the 2100 block of Flossmoor Road, the Cook County medical examiner’s office said.

The County Club Hills resident was pronounced dead within an hour, authorities said. An autopsy released Monday found he died of multiple injuries from a motor vehicle striking a tree, the medical examiner’s office said.

Flossmoor police did not respond Monday evening to a request for details.