BLACK HAWK, S.D. (AP) – The South Dakota Department of Transportation says a sinkhole near an interstate in Black Hawk no longer poses danger based on an engineering study that did not find any voids under the road.
DOT hired Rapid City-based FMG Engineering to look for underground abnormalities after the sinkhole exposed that part of the Hideaway Hills community was built over an abandoned gypsum mine.
Test results of the borings revealed none of the areas identified as anomalies were a void or anything else that would cause concern for the integrity of the interstate.
Both DOT and the state “are confident there is no threat to I-90 because of the mine discovery.”