Fortescue Metals Group suspended operations at Solomon Hub on September 30 when a drill and blast crew member was fatally injured after falling into a void.
This follows the death of a 52-year-old maintenance worker at CITIC Pacific Mining's Sino Iron mine on September 17.
The worker was fatally injured when he fell from a conveyor walkway to the ground below.
DMIRS extended its condolences to the family and workers affected by the tragedies.
In a statement the department said the fatalities should serve as a profound reminder to the mining industry of the importance of making safety the number one priority.
A report into 52 fatal mining accidents in WA over a 13-year period, from 2000-2012, found falls were one of the top 10 critical activities that led to fatalities during that period.
The other nine critical activities were departure from original equipment manufacturer procedures; run-away vehicles; vehicle over edge; vehicle collisions; electrical contacts; rock falls; pit wall failures; in-rush situations; and tyre handling.
DMIRS has put together a hazard register of all WA mining fatalities from 2000-18 that can help miners pinpoint onsite hazards that may cause fatalities or serious injuries.
The hazard register also shows how hazards can impact different occupation groups and identifies the activities and tasks being undertaken at the time fatalities or serious injuries occurred.
This can help identify potential precautions or preventative measures.