A 23-year-old Hyattsville man was killed when he was thrown from an all-terrain vehicle in Southeast Washington.

According to D.C. police, at about 6 p.m. Sunday, Michael Allen Brown was riding on a 2005 Yamaha four-wheel off-road vehicle in a grassy area near Oxon Run Park and the 900 block of Valley Avenue Southeast. Brown tried to enter the roadway when the vehicle struck a curb and a utility pole. Brown, who was not wearing a helmet, was tossed from the four-wheeler and sustained severe head trauma.

The incident is under investigation.