Hecla Mining said on Monday that production at its Idaho mine was hit after it suspended operations following a fire incident, sending the shares of the largest US silver miner down over 8%.

The company said a “fall of ground” incident occurred in one of the shafts at its Lucky Friday mine where the repair works were underway.

A “fall of ground” involves a collapse of a part of the mine shaft or tunnel roofs or walls crumbling.

No personnel were in the mine at the time of the failure, Hecla said, adding that it was working on a plan to resume production and would update 2023 outlook once that happens.

“A prolonged shutdown of operations at Lucky Friday following the ground fall/fire at the #2 shaft could materially impact 2023 guidance with the mine accounting for about 30% of our 2H23 consolidated EBITDA forecast,” said analysts at RBC Capital Markets.

“While management is working on a remediation plan, we expect this issue will further pressure near-term FCF (free cash flow) generation,” the analysts added.

Shares of the company fell to $4.18 in morning trading.