RAPID CITY, S.D. (Rapid City Journal) — The South Dakota Department of Transportation has hired an engineering company to study the safety of Interstate 90 near Black Hawk after a nearby sinkhole exposed an old mine. The DOT is contracting with FMG Engineering of Rapid City to look for underground abnormalities. The study is expected to begin the last week of May.
A dozen families had to evacuate their homes after a massive sinkhole opened in a nearby subdivision. It exposed the fact the subdivision was built over the abandoned gypsum mine. FMG Engineering will determine the stability of the interstate.