A dust storm shrouded the Interstate-10 highway south of Phoenix leading to numerous vehicle accidents that resulted in the deaths of at least four people and left others seriously injured. An element that jumped out at me about this story is that authorities told reporters they didn't know how many people were injured. They didn't even provide an estimate.

As the Arizona Republic reports:

About 20 vehicles were involved, the Department of Public Safety said. Authorities first responded to the scene at about 11 a.m.

DPS officials said several vehicles caught fire after a commercial vehicle exploded. An unknown number of patients were seriously burned or received traumatic injuries.

A hazardous-materials team was sent to the scene.

One semi appeared to be completely consumed by fire and remained smoldering more than an hour after the pileup was first reported. Possibly two other vehicles appeared to have caught fire.

Winds reached 25 to 30 mph gusts at the time of the accident, prompting the National Weather Service to issue a wind advisory at 11:55 a.m.

Gusts were expected to increase in excess of 30 to 45 mph as the afternoon wears on.