ST. CLAIR, Ohio (AP) — A driver was killed Wednesday when a large steel coil fell from a semi-tractor trailer and struck an SUV on a southwestern Ohio highway.

The accident on US Route 127 in St. Clair Township occurred around 6:20 a.m., according to the Butler County Sheriff’s Office.

It wasn’t immediately clear what caused the coil to become unsecured and fall from the truck, which was traveling northbound on the highway. The coil ended up in the southbound lane, where it struck the SUV.

The driver of the SUV was pronounced dead at the scene a short time later. The driver’s name has not been released.

No other injuries were reported in the crash, which remains under investigation.