Jama Jarrett said four of the still-unidentified workers had not yet returned to work, versus previous reports of one.

The workers made up seven of 11 passengers on a mantrip that was travelling at the mine on October 10 when the unit derailed and crashed into a rib.

“Two are off with arm/shoulder injuries, one with an ankle or knee injury and the other with a back injury,” she said.

“The miner with the back injury was still in the hospital as of [Wednesday] night.”

Jarrett said a state report on the accident reflected that the mantrip rolled down an incline after its brakes failed to engage. After derailing, the unit then hit the mine wall head-on.

Both federal and state investigators, along with the unit’s producer, were due onsite earlier this week to test the mantrip for any mechanical errors that may have prevented the brakes from engaging. As of Thursday, no evaluation results were available.

Neither the US Mine Safety and Health Administration nor the WVOMHST released the maker of the personnel carrier or the names of those involved.

The Roundbottom mine is operated by Massey subsidiary Elk Run Coal.