LEBANON, Mo. -- The cause of a crash that killed a race-car driver remains under investigation. It was the first death in the track's 18-year history.

Michael Roberts was killed during practice Saturday at Lebanon I-44 Speedway. His car hit the wall on a curve.

"We're going to look at everything we can to figure out why this happened," track manager Gregg McKarns said Sunday. "We should be able to tell once we get all of our facts gathered and have our experts look at anything."

Roberts, a 50-year-old driver from Milwaukee, was the only driver on the track when the crash occurred, McKarns said. Roberts was pronounced dead at a hospital.

It's not unusual for drivers from northern states to come to southern Missouri to practice, McKarns said. Roberts was not a regular at Lebanon.

"It's just one of those freak deals," McKarns said. "Auto racing is a dangerous sport, as is anything in life."