The driver of a semi was seriously injured Monday at 3:16 p.m. when the northbound semi ran off Highway 52 into a ditch just north of Olmsted County 7.

Troy M. Lounsbury, 39, of Castle Rock, Minn., was transported to St. Marys Hospital in Rochester by Mayo One after he was extricated from the cab.

The Chatfield Police Department, Olmsted County Sheriff's Department and Gold Cross assisted at the scene.

The Minnesota Department of Transportation reported that the highway was closed about six miles north of Chatfield for more than an hour shortly after the accident. By 6 p.m., traffic was again flowing on the southbound lane and authorities still on the scene were allowing traffic to move through the north lane.