WINDHAM (AP) – The death of a teenage boy whose body was found in a sport utility vehicle parked in the driveway of a home was caused by accidental carbon monoxide poisoning, authorities said Friday.

Eric Stover, 13, of Harrington was traveling with family friend Clarence Grant, 42, and Grant’s two teenage daughters. The four were staying Wednesday night at the home of a relative in Windham, said Stephen McCausland of the state Public Safety Department.

While Stover and the girls stayed in the house, Grant slept in the SUV. But at some point during the night, Stover decided that he preferred to stay in the vehicle and joined Grant, who would periodically run the engine to keep warm, McCausland said.

Grant left the SUV sometime after sunrise, leaving the boy inside, and returned about an hour later to find that Stover was dead, the spokesman said.

No charges have been filed in connection with the death. McCausland said the case will be reviewed by either state or local prosecutors.