The St. Clair River Tunnel between Port Huron, Michigan, and Sarnia, Ontario, has reopened for for rail traffic.
Canadian National finished laying new tracks in the tunnel, which had been closed after a June 28 derailment involving 46 cars and a mid-train DPU.
There were no injuries in the derailment, but sulfuric acid was spilled and had to be cleaned up.
“The spill caused no harm to the environment or to public safety as it was completely contained to the site of the derailment. The tunnel suffered only minor cosmetic damage and there was no impact to its structural integrity,” a CN spokesperson said.
Investigators have determined that the derailment began on the Canadian side of the border and therefore the Canadian Transportation Safety Board is leading the investigation.
During the tunnel closure, CN rerouted some trains between Toledo and Buffalo, New York, via CSX and Norfolk Southern.
Some CN trains were rerouted via Canadian Pacific routes.
The St. Clair River links Lake Huron and Lake Erie.