Since October 2020, four massive pillar collapses have occurred in limestone mines. Each was accompanied by a powerful air blast and the formation of a large surface sinkhole. Fortunately they did not result in any injuries. Another massive pillar collapse occurred in 2015, and in that instance three miners were seriously injured by the air blast. All of these collapses occurred where floor mining, or benching, had substantially increased the height of the pillars. Three of them occurred in “legacy” areas where mining was completed many years ago.
MSHA has resources available to raise awareness and avoid these accidents at underground mines, particularly limestone mines, that can result in areas where benching has occurred.  Please use resources on this page to help you avoid the dangers of pillar collapses.
For questions regarding this initiative, or to register for one of the upcoming MSHA Stone Mine Pillar Collapse Seminars below, please contact PillarInitiative@dol.gov.  Seminars are being scheduled in coordination with MSHA Enforcement District offices.  If a seminar for your District has not been scheduled, please check back or email us.  When registering, please provide your full name, company or organization, phone number, and the date of the seminar you would like to attend. 
Upcoming Presentations/Seminars
None scheduled.
 
Past Events
- Mine Xchange: SME Annual Conference and Expo
 https://www.smeannualconference.com/
 Where: Denver, CO
 When: February 26-March 1, 2023
- 33rd Central Pennsylvania Geotechnical Conference
 https://central-pa-asce-geotech.org/
 Where: Hershey, PA
 When: April 5 – April 7, 2023
- Southeast Mine Safety and Health Conference
 https://southeastmineconf.org/
 Where: Hoover, AL
 When: November 2-November 4, 2022
- Kentucky Professional Engineers in Mining Seminar
 University of Kentucky/SME
 Where: Lexington, KY
 When: August 19, 2022
- International Conference on Ground Control in Mining
 SME ICGCM
 Where: Canonsburg, PA
 When: July 26, 2022
- National Lime Association Annual Conference
 National Lime Association
 Where: Nashville, TN
 When: June 14, 2022
 
- Metallurgical Coal Producers Association
 Professional Engineers in Mining Seminar
 Where: Russell County Conference Center
 When: March 31, 2022
 
- Vincennes District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: January 20, 2022
 
- Barbourville District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: January 18, 2022
 
- Norton District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: January 12, 2022
 
- Dallas and Birmingham Districts Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: January 11, 2022
 
- Duluth District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: December 16, 2021
 
- Madisonville District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: December 15, 2021
 
- 2021 Underground Stone Safety Seminar
 Where: Louisville Marriott Downtown, Louisville, KY
 When: December 7 - 8, 2021
 
- Warrendale District Stone Mine Pillar Collapse Seminar
 Where: Virtual, via Microsoft Teams
 When: November 18, 2021
 
- Morgantown District Stone Mine Pillar Collapse Seminar 
 Where: Virtual, via Microsoft Teams
 When: November 16, 2021
 
- Mt. Pleasant District Stone Mine Pillar Collapse Seminar 
 Where: Virtual, via Microsoft Teams
 When: November 9, 2021
