 Gordon Moore Park in Alton will be closed to further notice after a sinkhole opened up at the turf fields near the entrance to the park on Wednesday morning. No one above or below ground was injured in the collapse, reportedly caused by surface subsidence according to New Frontiers Materials that operates mining in that area of Alton. The sinkhole, believed to be around 100 feet deep, swallowed up a section of turf between a soccer and football field along with a large light pole.