Underground voids from abandoned mines pose danger to people and property when land collapses

Associated Press

Swaths of Pennsylvania and many other states are honeycombed with old, unstable mines that can cause the earth to suddenly give way. The phenomenon is known as “mine subsidence” — and it poses a threat to people and property alike. That’s what officials near Pittsburgh fear happened Monday evening when 64-year-old Elizabeth Pollard went missing. A sinkhole appeared about 20 feet from where she had parked her car, in an area above an old coal mine. Federal officials say there are as many as 500,000 abandoned mines in the U.S.