Contents from an overturned tractor-trailer spilled onto a DeKalb roadway Monday, prompting hours-long road closures and hazardous materials crews to respond to the scene.

The exit ramp from I-675 north to I-285 west was blocked while hazmat crews worked to clean the area. The ramp reopened about 11:30 a.m., according to Channel 2 Action News.

The material on the truck remained a mystery Monday afternoon.

“Unclear on what material is on the truck at this time,” DeKalb police Maj. Stephen Fore told The Atlanta Journal-Constitution.

And it was not clear how the truck overturned.

No one was injured in the incident, Fore said.