(Rosemount, MN) Learfield Wire Services/TTWN Media Networks -- Rosemount police say they have taken into custody a truck driver who was hauling a boulder that dislodged and crashed into a car Monday killing a mother and daughter.

33-three-year-old Joe Czeck, the owner of Czeck Services, was arrested Wednesday. Rosemount police say 67-year-old Karen Christiansen and her 32-year-old daughter, Jena Christiansen, were killed late Monday afternoon when their car was hit a boulder that weighed an estimated weight of 800 pounds.

Investigators say they tracked down the commercial vehicle's owner and identified and arrested Czeck in Inver Grove Heights. Police officials say investigators used images from surveillance video at the nearby Flint Hills refinery to identify the truck.