A teen-age male died in Brooklyn yesterday when he lost control of the dirt bike he was driving and hit his head on the concrete. He was not wearing a helmet, police said.

The teen was riding his motorcycle in the 4200 block of Thayer St. at 1: 30 p.m. when the accident occurred, said Officer Raymond Howard of the city traffic enforcement section. Police said the teen died at the scene.

"He was so young, he didn't know how to ride," Howard said.

Police said late last night they had not identified the teen.

Pub Date: 6/20/99