Collapsed mine that caused Alton sinkhole was active limestone operation - St. Louis Post-Dispatch
- Collapsed mine that caused Alton sinkhole was active limestone operation St. Louis Post-Dispatch
- Soccer field damaged in Alton collapse KSDK.com
- Massive sinkhole collapses soccer field at Illinois park Fox News
- Giant sinkhole forms at center of soccer field in Illinois park: Watch USA TODAY