UPDATE: After the Louise bridge over HWY99 was found to be structurally sound by Cal Trans engineers, motorists were allowed back on the freeway shortly after 2pm.

Flames and heavy black smoke mushroomed over the Louise Avenue bridge over Highway 99 shortly after 10 a.m. Tuesday morning after a southbound truck crashed into the concrete bridge support in the center of the freeway.

Traffic backed up in both directions of Highway 99 until engineers can inspect the integrity of the bridge. Yosemite Avenue also backed up with freeway traffic exiting the freeway. Highway 120 Bypass was at a standstill as late as 11:30.

The entire cab of the large KTX trucking rig out of Sacramento separated from the engine compartment and the trailer and shot across the northbound lanes with the driver remaining in the cab. Witnesses said the truck's tires exploded as well as the gas tanks as one woman driving on Louise Avenue parked her car and ran through the black smoke on the bridge, down the embankment and found the driver sitting in the passenger seat with a gash on his forehead and described as incoherent.

Sandra Gardere said she is a medical assistant out of work currently from the effects of being in a rear end crash where she was the victim. She said she kept talking to the driver who was trying to go to sleep and tried to keep him talking placing a towel on his head wound.

Gardere said he didn't remember what happened and couldn't answer the simple questions of what day it was or what state he was in or his destination.

CHP ordered the REACH helicopter in to the scene and transported the driver to an area hospital after landing in the northbound lanes of Highway 99 north of the crash scene.

Officers couldn't predict when the freeway would reopen and were turning cars around to head them away from the crash location.