All lanes on the inner loop of the Capital Beltway near Connecticut Avenue in Maryland reopened Friday roughly seven hours after a tractor-trailer overturned.

The driver of the truck was “severely pinned” inside the cab but was conscious during the incident and was rescued, according to Pete Piringer, a spokesman for Montgomery County Fire. Piringer said the driver was taken to an area hospital with serious but non-life-threatening injuries.

He said the truck was carrying pallets of test tubes and that a hazmat team was brought in to clean up some fuel that spilled onto the roadway. The crash happened around 5:20 a.m., and the roadway still had three lanes closed at 11 a.m., with one lane getting by. Around noon, all lanes of the roadway reopened.

The cause of the crash wasn’t immediately known. But Piringer said traffic was lighter than normal and that some drivers are speeding. Combined with rainy weather, that factor could have contributed to the crash, but it is not known at this time, he said.