GAINESVILLE, Va. -- A Manassas man has been charged with driving under the influence after his pickup truck rear-ended a van Monday morning, killing an 8-year-old boy, Prince William County police said.

Police said the crash happened just before 6 a.m. at the intersection of Lee Highway and Somerset Crossing Drive in Gainesville.

A van had stopped at the red traffic light to make a left turn from northbound Lee Highway onto Somerset Crossing Drive when a pickup truck drifted into the lane and rear-ended it, police said.

A 20-year-old male driver, a 52-year-old woman and an 8-year-old boy were in the van.

The boy, Joshua Adams, of Warrenton, Va., was lying in the rear seat without a seatbelt and was thrown forward into the center console, causing severe injuries, police said.

Adams was flown along with the woman to an area hospital. The boy later died.

The driver of the van was treated at the scene for his injuries.

The pickup truck driver, Rodney Aaron Martin, 22, of Manassas, was taken to a local hospital and treated for his injuries.

He was charged with driving under the influence and released on a magistrate's summons. He is set to appear in court June 13.

The investigation is ongoing, police said.