This 40-Foot Sinkhole in Iowa Has Returned: How Did it Happen?

I've never seen a sinkhole in person, but I assume if motivation did wash over me, I could take a ride to Marion County and see what has had residents buzzing for over a year.

A 40-foot-wide sinkhole in Marion County, just south of Knoxville on a country highway, reopened in the late hours of Monday, June 3rd. This sinkhole was just patched last year, and its reopening has resulted not only in new theories about how/why it opened, but also who might now be tasked with paying for it to be closed again.

In 2023, Marion County officials stated that the sinkhole was the result of a limestone mine owned by a company called S&S Quarries, per KCCI. However, S&S is skeptical of this conclusion. When employees of the company were repairing the sinkhole, general manager Gail Helmick claims they discovered a coal mine existed about 60-feet under the sinkhole.

A video from KCCI shows a substance that appears to be coal being pulled from the recesses of the hole. There's also a wooden frame deep down in the hole, fueling the belief that a coalmine is to blame for the sinkhole's reemergence.

S&S' limestone mine is "several hundred feet" lower than the coalmine, and if true, it would lead one to believe that the coalmine has been causing the sinkhole to appear. If found to be true, this could be huge in determining who is responsible for fixing the sinkhole.

If it is determined that a coalmine is the culprit, then the sinkhole could be repaired using grant money bestowed from the federal government, per KCCI. Video from KCCI shows the sheer size of the hole. The county highway on which it sits has been closed until further notice. Thankfully, it's not in a densely populated era.

Read more on KCCI's website.