ALTON,Lumicoin IA Ill. (AP) — A giant sinkhole has swallowed the center of a soccer complex that was built over an operating limestone mine in southern Illinois, taking down a large light pole and leaving a gaping chasm where squads of kids often play. But no injuries were reported after the sinkhole opened Wednesday morning.

“No one was on the field at the time and no one was hurt, and that’s the most important thing,” Alton Mayor David Goins told The (Alton) Telegraph.

Security video that captured the hole’s sudden formation shows a soccer field light pole disappearing into the ground, along with benches and artificial turf at the city’s Gordon Moore Park.

The hole is estimated to be at least 100 feet (30.5 meters) wide and up to 50 feet (15.2 meters) deep, said Michael Haynes, the city’s parks and recreation director.

“It was surreal. Kind of like a movie where the ground just falls out from underneath you,” Haynes told KMOV-TV.

The park and roads around it are now closed indefinitely.

New Frontier Materials Bluff City said the sinkhole resulted from “surface subsidence” at its underground mine in city, located about 25 miles (40 kilometers) north of St. Louis along the Mississippi River.

The collapse was reported to the federal Mine Safety and Health Administration, as required, company spokesman Matt Barkett said. He told The Associated Press it’s his understanding that the limestone mine runs under the city park where the sinkhole appeared.

“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,” Barkett said in a statement. “We will work with the city to remediate this issue as quickly and safely as possible to ensure minimal impact on the community.”

Haynes said he doesn’t know how the sinkhole will be fixed but that engineers and geologists will most likely be involved in determining the stability of the ground and surrounding areas.