A blinding dust storm rolled across an interstate highway, causing a string of fiery crashes that killed at least four people and injured 42.

Authorities began pulling apart crumpled tractor-trailer rigs in search of other bodies early Thursday.

Twelve big rigs, along with a bus and nearly a dozen other vehicles, crashed Wednesday night on Interstate 10 (search), authorities said.

Two wrecks were in the Tonopah area, about 45 miles west of Phoenix; a third was 75 miles west of Phoenix.

One pileup began when a passenger vehicle stopped in the middle of the road, authorities said.

"This dust storm came in pretty quick," said Officer Erick Anspach of the Arizona Department of Public Safety (search). "Some drivers reported having only a second or two until impact."

The accidents shut down the interstate, and emergency crews initially had a tough time reaching the crash scene, according to the DPS.

"We could see nothing but dust and smoke" upon arriving, said firefighter Nate Ryan.

Several vehicles caught fire after the collisions, DPS spokesman Steve Volden said.

One of the dead victims was in a car that got wedged under a truck, Volden said. The second fatality was a truck driver.

Injuries ranged from cuts and scrapes to life-threatening.

The bus was apparently a charter belonging to Americano USA (search). State public safety Officer Norman Jones said the bus was westbound but he did not know its point of origin or its destination.

The bus was carrying 24 people, including two drivers, one of whom was in serious condition, Volden said. Officers didn't know whether any passengers were among those injured or killed.