FOND DU LAC, Wis. (WTAQ) - Wind is believed to have caused a semi rollover which shut down part of Highway 41 Wednesday. 

State Patrol officials say a Fab Express semi driven by Osvaldo Rodriguez overturned around 12:30 p.m. near Lincoln Road in Fond du Lac County. The rollover blocked both southbound lanes. 

Investigators think wind caught the empty trailer and knocked it over. Rodriguez had to be pulled from the truck and is hospitalized in critical condition.