The operation was due to begin ramping up to peak production from late-2021, but a restart date is now unclear after the incident caused one loss of life and one serious injury.

The coal mine had been progressing through re-establishment after Mastermyne was handed a $660 million mining services contract from mine owner Sojitz Blue in May 2021.

Mastermyne managing director Tony Caruso extended his condolences to those affected by the incident.

“This is a tragic event, and our immediate thoughts are with the family, friends and workmates of our employee,” Caruso said.

Mastermyne has already begun to scrutinise the cause of the event and will inform the public as new details come to light.

“The safety and wellbeing of our staff is one of our core values. The cause of the incident will be thoroughly investigated, and we will continue to support the family and our work colleagues,” Caruso said.

The mine was due to employ up to 180 people at peak production, with 11 million tonnes of coking coal to be sourced over the mine’s lifetime.

Mining and Energy Union Queensland District president Stephen Smyth said the union would aid in the investigation.

“We thank mines rescue and first responders for their attendance at the scene,” Smyth said.

“Union inspectors are attending the site and will undertake a thorough, independent investigation.”

The incident at Gregory Crinum follows a similar closure at OZ Minerals’ Prominent Hill gold mine in South Australia in early September.

Operations were temporarily suspended at Prominent Hill after an incident involving heavy machinery.