Investigators are still looking into why an overpass near Cincinnati collapsed during demolition work, killing one worker.

The collapse left tons of steel and concrete blocking the southbound lanes of Interstate 75. It killed one worker and injured a tractor-trailer driver, according to the Associated Press.

Workers began removing debris from the collapse on Tuesday afternoon and completed the work by nighttime, allowing the lanes to reopen. They made minor repairs as well.

Fortunately, the collapse happened during a period of light traffic on I-75, which likely reduced the number of casualties on a major artery that carries 178,000 vehicles per day. It is located about five miles north of the Ohio River.

Cincinnati Police Chief Jeffrey Blackwell said that the accident could have been “significantly worse” and that it was only because of timing that there weren’t more fatalities, according to the report.

Brandon William Carl, 35, of Augusta, Ky. was the worker killed in the accident. His body was removed from the rubble using air bags and other special equipment.

The injured driver is Eric Meyers of Howell, Mich., who was taken to the hospital with minor injuries after he had slammed into the overpass as the debris crashed onto the roadway, according to the report.

Carl was operating an excavator at the time and was crushed by the falling debris, according to a Cincinnati.com report.

Investigators first examined the scene before the roadway could be reopened and normal traffic could resume. Cincinnati authorities and Kokosing Construction Co. are conducting a forensic investigation into the cause of the bridge collapse, and the Occupational Safety and Health Administration is looking into Carl’s death.