Westbound traffic on Interstate 90 was shut down for more than five hours early Wednesday morning because of a truck-vs.-semi collision near mile marker 111 east of Missoula.
The Montana Highway Patrol said the four occupants of a Ford F-150 are lucky to be alive after slamming into the semi, which had just crashed into a bridge rail and become disabled.
All truck passengers were taken to St. Patrick Hospital shortly after the 4:50 a.m. crash. Three received minor injuries; a fourth, who was not wearing a seat belt, was severely injured.
The semi driver, who is from New York, was cited for careless driving. Montana Highway Patrolman Andy Novak said the trucker also failed to promptly put out orange triangles or flares to indicate a wreck.
A passenger in the semi was also slightly injured.
Traffic was rerouted to the frontage road until about 10:18 a.m., said Novak.
The semi crash occurred just after a rise in the road, making the disabled rig difficult to see for westbound traffic.
The Ford truck's driver, who is from Helena, first struck the semi's axle before plowing into the back of the semi itself.
Novak said the circumstance of the semi's wreck "is consistent with the driver nodding off to sleep."