MONTROSE, Wis. (CBS 58) -- A driver and a bystander were injured in a crash on State Highway 69 in Dane County Tuesday, Oct. 12.

Police say it happened in the town of Montrose. Deputies responded to what was originally a crash involving a car and power pole around 9:40 a.m. 

The driver, 23-year-old David Petershein of Viroqua, was southbound of Highway 69 when he crossed the centerline and struck a power pole, police say.

Officials say a good Samaritan stopped to help and was outside her vehicle when a semi-truck passing through hit a guide wire from the power pole that had been struck, causing the pole to snap and hit the good Samaritan. 

Both the driver and bystander were transported to local hospitals. Petershein sustained minor injuries. The bystander struck by the pole sustained serious and possibly life-threatening injuries.

The semi-truck driver was not injured and remained at the scene.

State Highway 69 south of Paoli is expected to be closed in both directions until at least 2 p.m.