SPOKANE, Wash. - The Spokane Police Department is investigating a collision involving a semi-truck and a man that happened in Downtown Spokane early Thursday morning.

Police said the incident happened around 1:30 a.m. on the intersection of Main Avenue and Browne Street.

Initially police said believed the victim has been struck by a semi-truck.

Officers said they found the man lying in the roadway and quickly provided first-aid until AMR paramedics arrived.

But the truck driver told police he stopped for the man to cross the street and that is when the man climbed up and tried to board the truck.

The trucking company told KREM that the victim then fell and was injured.

The man was taken to the hospital with what police said are life-threatening injuries. The driver of the truck is cooperating.

Traffic was impacted for hours while authorities investigated. Roads were reopened shortly after 6:30 a.m.

Spokane Police say they are still investigating the evidence from the scene. Anyone who may have witnessed the collision is asked to call Crime Check at 509-456-2233.