Donkin coal mine in Cape Breton hit by another rockfall

The reopening of Cape Breton's Donkin coal mine, which shut down last week for a brief summer vacation period, has been delayed by a rockfall.

Canada's only operating underground coal mine was scheduled to start back in limited production Monday morning, but the Nova Scotia Department of Labour said maintenance workers discovered a rockfall partway along the mine entranceway around 1 a.m.

There were no injuries.

The rockfall is not near the coal-cutting operations, which are deep under the Atlantic Ocean off the coast of Cape Breton Island near the community of Donkin.

Stop-work order issued

The provincial labour department issued a stop-work order at the mine following an inspection Monday.

Coal mining cannot resume until the company has determined what led to the rockfall, said Scott Nauss, the senior director of inspections and compliance with the labour department.

He said the company also needs to come up with safeguards to prevent a recurrence.

Nauss said the rock fall was about 10 metres in length, six metres wide, and a metre-and-a-half deep.

The mine has been limited to active work in two small sections since January after a series of roof falls last year.

Nauss said it was surprising that a rockfall occurred in tunnel number 2, which is the main entranceway into and out of the mine.

Nauss said a preliminary report from the mine operator indicates the rockfall was less than halfway along the main slope. The mine extends at least two kilometres out under the ocean.

The mine operator, Kameron Collieries, said in an email that part of the roof fell in on Sunday.

"This mine tunnel was first driven in 1984 and had not had any issues since then," the company said.

"The area and nature of this event is unrelated to the stress-related issues experienced in the last half of 2018."