Police say a man died Wednesday night after driving into the Long Island Sound in Riverhead.

Witnesses say the man was driving fast when he went down the beach access ramp at the end of Roanoke Avenue just before 7:30 p.m.

Witnesses say the unidentified man continued across the beach and drove straight into the water, submerging his SUV. They say his car was 100 feet from the shore. 

Emergency crews were able to free the driver, but he wasn't breathing. Police say the 21-year-old was taken to the hospital and pronounced dead. He was the only one in the SUV.

The circumstances surrounding the incident are being investigated.