Smoke from a prescribed burn closed part of Interstate 40 and caused numerous accidents this morning — and that smoke could have contributed to one fatal accident.

The highway was closed in both directions between Williams and Flagstaff for about five hours. Arizona Department of Public Safety spokesman Bart Graves says the fatal crash involved two semitrucks and a passenger vehicle.  

"There was heavy smoke in the area when our troopers arrived on scene, you know the visibility was poor, but it’s too early to determine whether that in fact played a roll in all of these crashes," Graves said.

U.S. Forest Spokesperson Brady Smith said residual smoke likely settled along the interstate overnight as temperatures cooled. He said there were electronic signs in the area cautioning drivers about the possibility of smoke and says he's not aware of any missteps by forest officials.