The Ohio Department of Natural Resources provided its preliminary findings and timeline to ILN Friday.

“Both ODNR and MSHA (US Mine Safety and Health Administration) have determined that the incident was a combination of geology and gravity, and was not related to any mining violation,” it said.

The miners, Gary Dulkoski and Jacob Harris, were rescued in good condition on October 10 and neither requested admittance to the hospital.

They were trapped from about 9.30am by the roof fall and were rescued about 7.30pm. Most of the rescue work involved stabilizing the roof to ensure safety.

“Because of the location of the roof fall, rescue staff had to secure the roof, at the same time removing the debris so they could access the trapped miners,” ODNR officials said.

“About 50 cars of material were removed from the area. Once the debris was removed, [the] rescue team made eye contact with the miners through a three-by-four foot hole in the rock debris. The biggest challenge was ensuring the safety of both the rescue team and the miners because of the concerns that the roof might collapse further.”

Ultimately, the agency confirmed, the rescue team at Hopedale constructed a roof support protection canopy on the bed of a shuttle car, and the unit’s operator drove the machine inby toward the stranded miners. They were then able to crawl out and onto the shuttle car protected by the roof canopy.

A joint state and federal investigation continued Friday.

“ODNR Mine Safety inspectors will evaluate what can be done to better stabilize the mine roof in adverse conditions, and revise the mine’s Roof Control Plan, if needed,” investigators said.

Hopedale Mining has a state-recognized mine safety team, with four of them playing a significant role in the rescue. The team has consistently ranked in the top 10 of recent Ohio mine safety rescue competitions.

The Hopedale complex is controlled by Rhino Resource Partners. As of December 31, 2011, it had an estimated 27.7 million tons of proven and probable coal reserves, and an estimated 12.3Mt of non-reserve coal deposits.

Coal from the Hopedale mine is cleaned at the Nelms preparation plant on the Ohio Central Railroad and the Wheeling and Lake Erie Railroad in Cadiz, then it is shipped by train or truck.