Woman dies after being hit by semi-trailer during Ohio triathlon

Ohio police are investigating a fatal collision that left a 44-year-old bicyclist dead over the weekend.

Kristen Oswald, 44, of Royersford, Pennsylvania, was competing in the IRONMAN 70.3 Triathlon in Ohio with her husband on Sunday when she was fatally hit by a semi-trailer, police said.

Officers with Ohio's State Highway Patrol said Oswald traveled outside a designated safety zone for riders on the highway when the crash occurred.

She was pronounced dead at the scene.

Investigators are working to figure out why she may have traveled outside of the designated riding area in Delaware County, Ohio, about 35 miles north of Columbus.

Patrol spokesman Lt. Robert Sellers said the driver did not appear to be at fault. No charges had been filed as of Sunday night and the driver was released from the scene after the crash.

"We don't know why yet, but the bicycle traveled outside of the safety zone and into traffic," Sellers told ABC News on Sunday. "The driver stopped right after the accident. We did conduct a Department of Transportation inspection as well. But he does not appear to be at fault in any way."

Sellers called the accident an "extremely unfortunate situation" and offered his condolences to the woman's family as well the other competitors.

"This is a tragic accident. Our thoughts and prayers are with the family and also with the the truck driver because, I mean, it's an unfortunate situation," he said. "We're also praying for all those people participating in the competition as well. I'm sure they have heart heavy hearts … you would never think something like this would happen."