Thick fog seen in southern Arizona

TUCSON, Ariz. (AP) - An unusual amount of fog throughout southern Arizona created tough driving conditions for morning commuters.

The National Weather Service in Tucson says the area sees fog like this only once every couple of years.

Tucson was hit hardest, but the fog extended from Santa Cruz and Cochise counties all the way north to the Phoenix suburb of Chandler.

It may have contributed to a fatal accident in Casa Grande, authorities said. Two were killed when their vehicle collided with a tractor-trailer in thick fog conditions.

The fog began clearing up early Thursday afternoon.