Old Mine Shaft Cause Of Sinkhole
www.kwwl.com/news/dubuque/this-sinkhole-in-dubuque-was-eating-at-a-neighborhood-for-years-now-its-finally-sealed/article_a5253a2e-61fa-11ec-9fb7-837a3667806c.html
1–2 minutes
www.kwwl.com/news/dubuque/this-sinkhole-in-dubuque-was-eating-at-a-neighborhood-for-years-now-its-finally-sealed/article_a5253a2e-61fa-11ec-9fb7-837a3667806c.html