A northern Utah man whose right leg was cut off by a runaway trailer was in critical condition Saturday following surgery at a Salt Lake hospital.

Brett B. Hall, 25, Wellsville, was traveling on southbound I-15 near 21st Street when a utility trailer going in the opposite direction broke loose, went through the median and slammed into his semitrailer truck, the Utah Highway Patrol said.The trailer pinned Hall, whose left foot was nearly severed and right leg cut off below the knee, troopers said.

Ogden firefighters used extrication equipment to help paramedics remove Hall from the wreckage. He was transported by air ambulance from McKay-Dee Hospital in Ogden to LDS Hospital in Salt Lake.

The UHP said the driver of the truck pulling the utility trailer is Richard J. Mickelson, 28, Smithfield.

The runaway trailer also knocked a hole in the fuel tank of a refrigeration trailer Hall's truck was hauling, a dispatcher said.