Summary: A highwall failed and material spilled over the bund protection and onto the working bench below. This blocked access to part of the pit. While no workers were present in the area where the failure occurred at the time and no equipment was damaged, three workers were temporarily unable to egress the pit due to the access ramp being damaged when the highwall failed.
Recommendations to industry: A section 195 prohibition notice is in force prohibiting mining operations from taking place in this part of the mine.
Review the frequency of assessments of highwall stability and confirm appropriate triggers are included to increase frequency of assessments arising from events such as rain events and shot firing.
Mine operators should also review SB17-03 Rocks breach catch bund.