The southbound lanes of Interstate 81 near the Mount Crawford exit were closed for a few hours Monday because of a tractor trailer fire.

Officials say an empty tanker truck caught fire shortly after 11 a.m. and the cab section was destroyed. However, the driver was able to escape without injury.

Virginia Department of Transportation crews inspected the bridge over the North River because the truck hit part of the guardrail there and sent pieces into the water.

VDOT was checking to make sure the bridge is safe for traffic. The interstate re-opened just before 3:30 p.

Police say the truck driver believed he had an equipment failure so he hit the guardrail to slow himself down.

The state Department of Environmental Quality will also be coming out to inspect the scene because of possible oil contamination of the river.

However, an official said its unlikely the water was contaminated by oil or gasoline because the fire burned up most of the fluid.

The fire was large and could be seen for miles away.

"We could see the smoke from James Madison University, from the interstate, so it was pretty big," says Chief Robbie Symons, Rockingham Fire and Rescue.

James Madison University is roughly six miles away from where the fire took place.

Traffic backed up as far as six miles during the day. There was heavy traffic on Route 11 as motorists tried to avoid the interstate.

The northbound lanes were closed when the incident first occurred but authorities say those lanes re-opened quickly.