MADISON, Wis. - The veteran driver whose vehicle killed a promoter at a monster truck show told investigators he never saw the man walk into his path, authorities said.

It was the nation's second fatal accident at a monster truck show in a little over a week.

George Eisenhart Jr. suffered severe internal injuries when he was hit by the huge truck Saturday at the Motor Sports Monster Truck & Thrill Show at the Dane County Coliseum, the coroner said. The show was immediately halted.

The big blue truck with oversize tires was driven by its owner, Daniel Patrick, who authorities said has been a driver on the circuit for more than 20 years.

Amateur video broadcast on television showed a man walking in front of the truck.

"Our preliminary investigation shows neither Eisenhart nor the truck driver saw each other before the collision," Coroner John Stanley said at a news conference Sunday.

Authorities said Patrick would not be charged. Sheriff Dave Mahoney said it appeared all safety precautions had been taken and called the death "a very tragic accident."

"He knew he had hit something but obviously, he didn't know it was a person. ... He is taking this very hard," Mahoney said.

The U.S. Occupational Safety and Health Administration will investigate.

Eisenhart, 41, of Chardon, Ohio, was owner and president of Ohio-based Image Productions, which has been staging monster truck shows across the nation for more than 15 years.

Eisenhart had spoken proudly of the show's safety record the day before the accident, telling WKOW in Madison: "This is our 16th year, and I wish I had a big piece of wood to knock on right now, but we have not had an incident besides a gal slipping in the aisle at another location."

On Jan. 16, a 6-year-old boy was killed in a Monster Jam event in Tacoma, Wash. Sebastian Hizey was struck on the head by a chunk of metal that flew off a truck doing doughnuts. One man in the audience was seriously injured.