A man suffered serious injuries after crashing into a parked semi truck at a weigh station on Interstate 90.

The incident occurred in Billings, Montana, on Wednesday evening.

According to KPAX.com, the truck was parked near the East Laurel Exit and was waiting for service at the weigh station, when the Toyota Carolla slammed into the back of his rig. Local police said the car was traveling at highway speeds at the time of the collision.

Officers are unsure how the incident unfolded. “How could he miss a semi?” Trooper Gerald Perman told reporters.

The Toyota driver suffered “massive blunt force” and was airlifted to St. Vincent Healthcare. His current condition is unknown.

An investigation is underway, including a blood test to determine if drugs or alcohol were involved. The Toyota driver’s cell phone was also recovered, and police will try to determine if distracted driving was a factor.

The truck driver was not injured.