Alcohol may be to blame for a Saturday morning collision near Walcott Junction that killed a 49-year-old Colorado man and his 10-year-old passenger.

The Wyoming Highway Patrol says Leserio Garcia was headed west on Interstate 80 shortly after midnight when he rear-ended a semi that was parked on the side of the road near milepost 239.

Garcia's car rotated and rolled off the interstate coming to rest in the median on its roof.

Garcia was unbuckled and thrown from the car. His front passenger, Payton Garcia Edman, was wearing her seat belt. Both died at the scene.

The Patrol says suspected alcohol use and driver fatigue are being investigated as possible factors in the crash.​

They're also asking for the public's help in locating a semi driver that traveled through the debris field seconds after the collision.

A witness at the scene said the semi was pulled over in front of his vehicle, but left before law enforcement arrived.

Anyone with information is asked to contact dispatch at (307) 777-4321 and reference incident number P2018128149.