The wheel that crashed into an 18-wheeler early Wednesday, killing the driver, came off another big truck that was soundbound on Interstate 65, state troopers said.

Investigators said one of the outside wheels off the dual-wheeled rig came off, went south through the median and crashed into the windshield of the truck and killed the driver, 47-year-old Barry Keith Smitherman, 47, of Summitt Ridge Road, Madison.

Troopers said the driver of the truck who had the wheel to come off stopped at a gas station near Exit 322 in Falkville in Morgan County and realized he had lost a tire.

At the time of the freak accident, troopers and Limestone County Coroner Mike West had no idea where the 15-inch wheel came from.

“I’ve never seen anything like this,” West said. “It was certainly a freak accident, one in a million that something like this would happen.”

West said Smitherman, who has a wife, Patti, three sons and two daughters, died from massive head injuries. His funeral will be Saturday at 9 a.m. at Spry Funeral Home in Huntsville.

Smitherman had just left the Huntsville area hauling a load and was traveling north on the interstate just north of Athens when the accident occurred just after midnight.

“It appeared the wheel hit the truck head-on and jumped into the windshield,” West said. “It entered the cab of the truck and exited through the back top. The wheel was found about a quarter-mile south or behind the 18-wheeler.”

Smitherman was employed by First Fleet in Huntsville and had left Bardcor in Huntsville with a load of materials, West said.

After the driver got hit in the head, the truck left the pavement and apparently got stalled in the mud on the east side of the interstate. It came off the road and to a stop, West said.