Police are investigating an accident that left a teen dead and three others injured this morning.

Investigators say David Longford was driving a 2002 Toyota northbound on Grey Avenue when he apparently lost control. The vehicle smacked into a tree, causing it to flip over.

The crash ejected 16-year-old passenger David Ross, who was pronounced dead at Brookhaven Memorial Hospital Medical Center in East Patchogue. Longford and two other male teenage passengers were taken to local hospitals for non-life threatening injuries.

Officials say Longford, of Medford, had a learner's permit, but should not have been operating a vehicle without the supervision of an adult. Police also say he was speeding, and that slick roads could have been a factor in the accident.

All four of the teenagers attend Longwood High School. Ross was called a "fine student" in a statement issued by the district.

Police issued Longford a summons for unlicensed operation of a motor vehicle.