A piece of Iowa's past swallowed up a big portion of a front yard in Des Moines early Wednesday morning. A large sinkhole that’s estimated to be more than 30 feet deep, and roughly 20 feet across collapsed a yard on the city's south side.
State officials say the sinkhole likely formed due to the abandoned coal mines under the city.
"It's not like you walk outside your house too often and your yard's gone. That's pretty rare," says State Geologist Bob Libra. "You're probably seen some picture in the past from Florida, where they have very large sinkholes open and swallow house. We don't have anything that's usually that aggressive."
Coal is no longer mined in Iowa, but in the early 20th century it was the state’s number two industry. The Iowa DNR has an interactive mapshowing where coal mines are located around the state.
In addition to underground mining cavities, sinkholes are also seen in eastern Iowa when ground water dissolves limestone. Florida sinkholes are formed from dissolved limestone as well, but the humid climate of the Sunshine State makes them far more common.
