Photos by Stephanie Klein-Davis | The Roanoke Times

After acetic acid was spilled in a Roanoke County wreck on Thursday, Tony Rickman with Salem Fire & EMS and Steve McFadden with Roanoke Fire-EMS donned coverall suits and worked to neutralize the chemical.

A safety officer works the scene of the Roanoke County crash involving a truck hauling four types of explosive materials used in blasting. The truck (background) is being towed away.

A truck carrying more than 11,000 pounds of explosives wrecked on southbound U.S. 220 Thursday morning, snarling traffic heading into and out of Roanoke for four hours during the morning rush hour.

No one was seriously hurt in the wreck, and no explosives spilled onto the road. But authorities in Southern Roanoke County blocked a 1¹₂-mile stretch of the highway from about 6 to 10 a.m. between Yellow Mountain Road and Buck Mountain Road.

Traffic in each direction backed up for more than half a mile from those intersections, as police detoured northbound traffic onto Naff Road and southbound traffic onto Buck Mountain Road. More than a dozen cargo trucks were caught in the area that was blocked off.

"It's not very often that we have to shut down northbound and southbound 220 for four hours," said Charlie King, Roanoke County fire and rescue battalion chief. "I'd say it's a pretty serious incident. The truck's probably totaled."

The wreck occurred between the intersections of U.S. 220 at Suncrest Drive and Yellow Mountain Road about 5:30 a.m., said Officer Chris Brown of the Roanoke County police.

Police declined to give a cause for the accident Thursday afternoon, saying it was under investigation.

But a spokesman for the company that owns the truck said its driver was not at fault.

The truck was heading south when the driver, Boyd Miles, swerved to avoid striking a pickup truck that was pulling out of a work site on the shoulder of U.S. 220, according to Bruce Fox, operations manager of Austin Powder, the explosives company that owns the truck.

The truck fell into a ditch in the median, overturned, and smashed on its right side onto the ground.

Contractors for the Western Virginia Water Authority were there installing waterlines along U.S. 220 for a public water extension to Franklin County.

"Our drivers are trained in defensive driving, which means you don't drive into something, but you drive away from it," Fox said. "He probably made the best decision that he could to avoid something worse."

Gary Robertson, executive director for operations at the water authority, said its contractor had properly signaled the work area.

"The chances of danger are surely increased in areas like that," he said.

Aboard the truck were four types of explosive materials used in blasting, including 11,190 pounds of hydromite mixture, a liquid as powerful as dynamite, but more safe for transportation. There were also seven boxes of detonators, 135 pounds of explosion boosters and 250 pounds of hydromite tubes.

Each of the explosives was packaged in separate containers in compliance with regulations for moving explosives, said Roanoke County Fire Marshal Gary Huffman. The truck was traveling to a quarry in Pittsylvania County.

The wreck caused about 15 gallons of acetic acid, another substance aboard the truck, to spill onto the roadway.

About 9 a.m., after the truck was towed away, two firefighters who donned white coverall suits sprinkled sodium bicarbonate to neutralize the acid. After the traffic was cleared, a smell like vinegar lingered in the air.

The tie-ups had some tractor trailers missing deadlines on their routes.

"But at least I got a nap in," said Dallas Hall, who was driving cabbage and watermelon to Danville on Thursday morning.

The wreck wasn't the only morning rush-hour accident Thursday.

A two-vehicle collision on Orange Avenue occurred about two-tenths of a mile east of King Street and closed the right westbound lane for about 15 minutes after a 2005 Chevrolet sedan ran into the back of tractor trailer about 7:25 a.m.

The driver of the Chevrolet was charged with following too closely, state police Sgt. Steve McChesney said. A passenger in the car, Graynell Anderson, was taken to Carilion Roanoke Memorial Hospital. A hospital spokeswoman said Thursday afternoon she was listed in good condition.

Staff writer Neil Harvey and online producer Jordan Fifer contributed to this report.