DONKIN, N.S. -- The Donkin Mine was closed on Sunday – as far as coal production is concerned – after the second reported roof fall at the Nova Scotian mine in February.

Hughie MacArthur is a retired international representative with the United Mine Workers of America. He also worked for 30 years as an underground miner and was a mine safety coordinator. He says he knows first-hand that rockfalls are serious matters.

"I'm getting kind of tired of hearing that word - two more rockfalls, or one more rockfall," says MacArthur. "A rockfall is one of the most serious safety conditions you can have in a mine, besides gas.  It is one of the most.  It can happen out of nowhere."

In a news release, Kameron Coal, the company that owns the Donkin mine, reported a roof fall that happened on Thursday afternoon. While the company confirms nearly 40 miners were underground at the time, it says there were no injuries.

Eleven days earlier, Nova Scotia's department of labour reported another rockfall – which no one was hurt during.

The department says the two collapses happened at intersections in close proximity to each other.

A spokesperson for the Donkin mine confirmed via email that a stop-work order remains in effect at the mine. The stop-work order means staff can be inside to do things like maintenance of systems; however, the company is prohibited from mining coal while the order is in effect.

In addition, the mine also saw a roof collapse into an entrance tunnel in July, as well as a pair of collapses in December 2018. While no one has been hurt in any of the incidents, some wonder if it's only a matter of time.

"I know everybody hates to hear that word 'westray' that are not involved with coal mining, but the worker needs to understand that protection," says Hughie. "They gotta protect themselves."

Kameron Coal says department of labour inspectors are assessing the impact of the latest rockfall and will review remediation plans before any work begins. While the company says safety is their 'paramount consideration,' Hughie feels workers would be safer if they were unionized.

"If you don't have a union out there working for the workers, you're not going to have safety like it should be," says Hughie.

Meanwhile, a timeline for a return to coal production at the Donkin mine hasn't been established yet.