Workers evacuated in time from mine collapse, Alton sinkhole

ALTON — The underground mine that collapsed and left behind a massive sinkhole at a park here was an active limestone operation, the mining company confirmed Thursday.

Workers evacuated the mine in time, and no injuries were reported, the company said.

Security footage has circulated widely online that showed the collapse and resulting hole, which swallowed a light pole and a large portion of soccer turf at Gordon Moore City Park and left behind a gaping crater 50 feet deep and 100 feet wide. The collapse happened about 8:30 a.m. Wednesday, said Mike Haynes, director of Parks and Recreation for Alton.

The park closed on Wednesday, and it will remain off-limits until it is declared safe by federal mining regulators. Residents should not enter the park, the city of Alton emphasized Thursday.

Maryland Heights-based New Frontier Materials owns the mine underneath the soccer field. The mine is part of a limestone quarry that New Frontier acquired from Fred Weber Inc. in 2021. It produces crushed limestone and a high-calcium limestone product used in agricultural applications.

“We are fully dedicated to working with the City of Alton to remediate this issue swiftly and safely,” New Frontier CEO Mike Clarke said in a joint statement with the city of Alton late Thursday.

As of late last year, about 55 people worked at the mine, with 28 of those employees on jobs underground, according to the federal Mine Safety and Health Administration. Workers drill and blast limestone and haul it out via trucks.

It was still unclear Thursday morning what, exactly, caused the collapse. A New Frontier spokesman said the company didn’t yet know.

“The impacted area has been secured and will remain off limits for the foreseeable future while inspectors and experts examine the mine and conduct repairs,” a New Frontier spokesman said.

The Mine Safety and Health Administration, which regulates mines, is investigating the collapse. A spokeswoman for the Illinois Department of Natural Resources, which oversees the Office of Mines and Minerals, said the state does not regulate the limestone mine.

But by the end of the day Thursday, Illinois Gov. J.B. Pritzker had weighed in, offering MSHA assistance from the Illinois Department of Natural Resources and the Illinois Emergency Management Agency.

“The residents of Madison County deserve a thorough and well-communicated investigation into this incident to hasten their return to normalcy,” Pritzker said in a statement.

Alton Mayor David Goins said in a statement that the city…