(CNN) -- Three people died Tuesday when a sweeping dust storm impaired visibility on a major interstate in Arizona and caused a chain-reaction of car accidents, according to the state's Department of Public Safety.
Between 30 and 40 vehicles were involved in the Interstate 10 accidents, which also seriously injured five people, Officer Robert Bailey told CNN's sister network HLN. A total of 14 people were hurt, DPS spokesman Harold Sanders told CNN.
The collisions started fires, and many of the injured suffered burns, Bailey said.
Officials were asking motorists to avoid the affected stretch of I-10, near Casa Grande, Arizona, and south of Phoenix. The scene was a horrific sight even after fires were extinguished, Bailey said. Tow trucks were on the way to clear the road late Tuesday morning.
"There's still a lot of carnage and mess out here," Bailey said.
Officers in patrol cars are managing rolling traffic breaks to slow traffic, Sanders said. Motorists shouldn't drive faster than 30 mph in the area or in the vicinity of any dust storm, he said. If a driver sees a dust storm ahead, the first step should be to get off the road, he said.
I-10 from Phoenix to Tucson gets hit by 10 to 20 dust storms per year, mostly during the summer monsoon season, said Ken Waters, warning coordination meteorologist with the National Weather Service in Phoenix. But he wouldn't describe the Tuesday event as a storm, rather "a case of very localized dust being picked up and thrown across the highway."
Nearby farming could have contributed to Tuesday's conditions, Bailey said.
"What we see here is some farmland here that is very dry and was recently cultivated, and that may have contributed to this," he said.
Waters gave credence to that theory, saying that winds were clocked at 15 to 20 mph, not as strong as in typical dust storms, in which winds reach 30 to 40 mph. But the area also had seen little rain in the past few weeks, he said, exacerbating the dust problem.
CNN's Khadijah Rentas and Sara Pratley contributed to this report.