One miner has been found dead and two are still missing but feared dead after an inrush of water and silt in a shaft of the Velenje coal mine in what is the country's worst mining accident in over 20 years.

The accident happened at around 7pm on 20 January in the active part of Slovenia's sole operational mine, where coal is being extracted.

The sudden inrush of water hit a group of 14 miners operating the machinery. The majority managed to retreat to safety but three were unable to.

Rescue operation under way

One of them, who media say was a 23-year-old miner, was found dead late on 20 January, while rescue operation is under way to reach the other two, but the chances of them having survived are thought to be very slim.

According to coal mine director general Marko Mavec, rescuers and workers have been clearing the material manually but have now installed a conveyor system to assist with its removal.

"We expect that we will manage to clear what are an estimated 500 to 700 cubic metres of collapsed material today or in the coming days and reach the missing miners. While we remain hopeful for the best, we fear the worst," Mavec told reporters on 21 January.

Rescue teams can only work for four hours at a time with special breathing apparatus, according to media reports. Production at the mine has been suspended while rescue operation is under way.

Families of victims promised support

Visiting the site, Prime Minister Robert Golob pledged for the state to provide assistance to the families of those affected by the accident, as did the mine, indirectly owned by the state.

Golob moreover vowed for sufficient funds to continue to be allocated for safety investments in the mine.

Both him and President Nataša Pirc Musar expressed condolences to the relatives and co-workers of the dead miner, and thanked the rescuers searching for his missing colleagues.

The president also called for an in-depth investigation into the tragic accident, "so that similar tragedies can be prevented in the future and the safety of all miners ensured".

Investigation is under way with the chief mining inspector arriving at the site immediately after the accident. Police, criminal investigators and a state prosecutor are also examining the site.

The mine expressed deep regret over the tragedy. "Despite all safety measures, such accidents cannot be predicted or prevented in advance. We deeply and sincerely extend our condolences to the families and offer them all possible support."

Worst accident in Velenje in 20 years

This is the most severe accident at the Velenje coal mine since 2003 when two miners were killed and eight injured as a result of increased concentrations of gases. One miner was killed in an accident in 2014.

The worst ever accidents at the mine were in 1893 when a gas explosion killed 11 miners on 30 January, and a similar incident killed 21 more just 20 days later. In 1962, four miners died in an accident.

The last accident in Velenje was recorded in February 2024, when four miners were affected by an increased concentration of harmful gasses. None of them sustained serious injuries.

In Velenje coal is mined more than 500 metres underground. A distinct coal extraction technique is used where a large "wall" of coal measuring up to 170 metres in length and up to 18 metres in height is mined in a single slice, according to the company's website.

As the coal is removed, the area behind the miners is allowed to collapse, a process called controlled subsidence.

The mine is due to be closed as the country's exit from coal is planned for 2033.