Page 30 By Frank Giorno On June 20 1984 a rockburst occured at Falconbridge s No 5 shaft in Sudbu ry at the 4000 foot level The force of the rockburst was so intense that it measured 35 on the Richter scale and was felt in downtown Sudbury A rockburst is a spontaneous fail ure of rock structure that occurs in highstress mines Mining ac tivities such as blasting relieves neighbouring rock structures of pressure The release of the pressure causes explosive shift ing and collap se of the rocks that ca be signifc ant enough to mea sure on the Richter scale The force of the rockburst at Fal conbridge caused the collapse of backfll in an undercutand fll stope There were 200 workers at the mine that day and most managed to escape Four miners were bur ied under the rock and perished One of the miners survived for 27 hours when he was pulle d from the rubble by mine rescue teams but died on the way to the hos pital The four deaths deeply afected the Sudbury community The teams performed admirably but were not setup to succeed said T ed Hanley V ice Presidet of the Ontario Mine Rescue They were unable to safely reach workers due to repeated events being unequipped to extricate trapped workers from the burst zones and by lack of training in working in confded space The next month on July 6 1984 a rock burst at the Creigh ton mine in Sudbury reached 40 on the Leading to changes in Mine Rescue T raining Richter scale Fortunately the mine was closed for holidays and there were no casualties On December 17 another rockburst occurred at the Quirke Mine in El liot Lake Rockbursts were also re ported at mines in Red Lake and Kirkland Lake The Ontario government estab lished the Stevenson Commission to examine emergency prepared ness for rockbursts and ensuring the ground in the mines was stable to ensure workers safety After 17 months of public hearings visits to 15 mine sites and discus sions with mine management and unions the Stevenson Commission released its recommendations Stevenson made importan t recom mendations calling for improved monitoring for signs of rockbursts including training miners to identify signs of potential rock collapse Stevenson recommended mea sures that would reduce the oc curence of rockbursts through bet ter sequencing of mining activity and stablizing working areas to minimize stress and relieve rock collapses He also called for rock mechanics programs and re search into techniques for stabliz ing grounds in mining work areas The Stevenso n Commissi on also found the rockburst in 1984 at Fal conbridge Shaft No 5 indicated a need to improve emergency response training to inclu de han dling of emergencies caused by rockbursts rock falls wall col lapses and other nonfre emer gencies Ontario Mine Rescue training up to the 1980s focused on managing emergencies from explosions and fres in underground mines The purpose of mine rescue in Ontario is frst and foremost to save lives in the event of a mine fre In this the organization is ex emplary only one life has been lost in an underground fre since Page 28 of 1984 The Falconbridge Rockburst