Speed and driver inattention may be to blame for a deadly collision that closed down southbound Interstate 25 near Wheatland for nearly six hours Thursday afternoon.

Wyoming Highway Patrol Sgt. Kyle McKay says the call came in as a single-vehicle rollover, but it was actually a two-vehicle crash.

"A Dodge Ram 3500 was traveling southbound near mile marker 71 when a Chrysler 300 came up behind him and rear-ended the pickup," said McKay.

"The pickup was displaying an arrow board sign advising (drivers) to move over because there was a barricade crew that was picking up traffic control cones ahead," McKay added.

The driver of the car, 28-year-old Eric Verplancke of Montana, was not wearing his seat belt and died on scene.

The driver of the construction crew pickup was taken to the hospital where he was treated and released.

The Patrol says it was raining and the Interstate was wet at the time of the crash.

The crash had the southbound lanes near milepost 71 closed from approximately 12:35 p.m. to 6:20 p.m.