Indiana State Police investigators say INDOT was dumping a load of rock in the driving lane in order for a track hoe to pick up small amounts to place in the ditch adjacent to the westbound lanes.
INDOT had the driving lane closed to traffic.
Just before noon, a one-foot diameter rock rolled from the closed driving lane into the passing lane.
A grain truck traveling west struck the rock with its tire.
The rock bounced back toward the driving lane striking INDOT employee Michael Chasteen, 48, of Evansville.
He was taken to Deaconess Hospital with a serious leg injury.