A fiery, single-car accident early Saturday, which caused the driver to be hospitalized, remains under investigation.

Police said the 21-year-old driver was found on the ground outside the car wreck about 4 a.m. Saturday on Congress Street. The car's engine compartment was in flames, according to the report.

The car was traveling west on Congress when it went off the road, hit the curb and two stone walls before coming to rest against a tree, police said. The driver apparently crawled out of the driver's side window and indicated to police that there three other occupants in the car at the time of the crash.

Police, along with firefighters using thermal-imaging cameras in the woods nearby, could find no evidence of any passengers.

The driver was taken to Bridgeport Hospital for treatment.