MULLAN, Idaho -

Seven miners were injured in a rock burst at the 5900 level in the Lucky Friday Mine early Wednesday evening.

The Shoshone County Sheriff's Office got a call at about 7:50 p.m. Wednesday evening there had been a collapse of some sort at the mine. MedStar launched a helicopter to the scene to provide medical evacuation support, if needed.

It turned out that it wasn't a collapse but rather a rock burst happened at the 5900 level of the mine, injuring seven miners. A rock burst is typically a spontaneous, violent fracturing of rock. Previously, on Dec. 27, 2000, a rock burst at the 6020 level in the Lucky Friday Mine was so large it expelled 320 tons of rock. The seismic energy from that previous rock burst was recorded at Richter magnitude 2.4.

There were 20 miners in the Lucky Friday at the time of the incident and all have been accounted for. Seven miners reportedly had minor injuries and are in stable condition, though one of those seven miners was reportedly transported to Kootenai Medical Center in Coeur d'Alene.

Initially, when called for comment on this latest incident at the Lucky Friday, Hecla officials would provide no details, and said only that, "miner safety is our number one priority" and had no further comment. Shortly before 11 p.m. Hecla President and CEO Phil Baker arrived in Mullan and participated in a press conference held by the sheriff's office.

The Lucky Friday Mine has been temporarily closed down in the wake of Wednesday evening's rock burst.

This is the fifth incident at the Lucky Friday Mine this year, the third one that involved injuries to miners and the second one to happen in the last month.

On April 15, miner Larry Marek died in a cave-in in the tunnel he was working in with the amount of rock that came down the size of two buses stacked on top of each other. In the subsequent investigation into Marek's death, Mine Safety and Health Administration officials say Marek was working in an unusually wide tunnel that needed a pillar to help hold up the roof.

The investigators found "a substantial quantity of material fell on Marek after portions of that supporting pillar was removed to extract ore" and that "mine management has engaged in aggravated conduct constituting more than ordinary negligence by directing the pillar to be mined as the stope advanced."

Larry Marek's daughter took the findings by MSHA a step further by writing, in a comment on KXLY.com after MSHA released its findings, that "[t]here were miners that felt this was unsafe and management did not listen. They did expose my father to an unsafe situation. They removed a support pillar that was high in ore."

In early July there was a fire inside a storage area in the mine. Everyone was evacuated safely and no one was injured. Hecla later reported to MSHA that the fire had been started inadvertently by a discarded cigarette butt. Later in the month, on July 26, that Hecla reported was arson. The ATF investigated the incident along with the Shoshone County Sheirff's Office and later confirmed that it was in fact arson.

On November 17, miner Brandon Gray was trying to dislodge broken rock in a storage area when the material started flowing. Gray, a 26-year-old contract miner was wearing a safety harness attached to a self-retracting lanyard, however the safety line extended and did not lock before Gray was engulfed by the debris and he suffocated. Gray died two days later at Kootenai Medical Center.

Just two weeks ago, Hecla held a press conference in the wake of MSHA's investigation into Larry Marek's death, and at that meeting Hecla President and CEO Phil Baker said that the mine would make improvements in the facility based on MSHA recommendations.

"In this case the pillar appears to have failed so, yeah, we are changing our procedures with how we'll mine these pillars," Baker said at the time.

Baker also reiterated at that press conference that miner safety is a top priority for Hecla.

"If there's anything we want, it's to operate these mines as safely as you can possibly operate them and so when we look at these reports we look at opportunity to improve our activities," Baker said.