A 13-year-old died Saturday morning when he was thrown from his all-terrain vehicle, police said, after losing control of it as he drove on a street in Southwest Philadelphia.

The boy, whose identity was not released Saturday, was driving a 2002 Yamaha four-wheel ATV eastbound on the 5900 block of Elmwood Avenue. He was seen weaving in and out of traffic, police said.

Around 9:30 a.m., a preliminary police report said, the boy "lost control of his ATV, was ejected, and struck a pole and a tree."

No other vehicles were involved in the accident.

The boy was pronounced dead upon arrival at the Hospital of the University of Pennsylvania.

- Jonathan Lai