EL PASO COUNTY, Colo. -

The Colorado State Patrol says a 77-year-old man was found dead after he crashed his truck into a bridge pillar on Las Vegas Street.

The accident was reported at 10:25 a.m. on May 22, 2014.

Troopers say the man was northbound in a 1993 Ford Ranger when he went off the right side of the road and crashed into a bridge pillar underneath the Martin Luther King Jr. Bypass.

The truck came to a rest on its passenger side in a drainage culvert.

The man, who was not wearing his seat belt, was submerged.

An El Paso County Sheriff's Deputy and a bystander pulled the man out of the truck and tried to revive him.

Troopers believe a medical condition or falling asleep at the wheel may have contributed to the accident.

An autopsy will be performed to determine the man's cause of death.