Mankato (KMKO)-One person was injured in a three vehicle pileup on in Mankato yesterday.  The incident happed about 2:00 pm on Highway 169.  According to the State Patrol, a minivan and a van were stopped in the southbound lane in a construction zone.  A third vehicle, said to be a Freightliner semi, rear-ended the van, sending it into the first vehicle.  The driver of the van, 71-year-old William Lange of Dundee, was treated and released.  The driver of the semi was 35-year-old Terry McMichael of North Mankato.  The state patrol was assisted by Mankato Police and Gold Cross Ambulance.