The agency reported that 197 of its planned interviews with those involved with the mine and the explosion have been interviewed, with about 50 more interviews remaining.
As of August 25, officials have compiled 260 pieces of evidence.
Investigators are also nearing completion of mapping efforts; about 90% of the mine mapping has been performed with the remainder to be completed once water is pumped from UBB’s headgate 22 section.
“Investigation teams plan to revisit the longwall face to search for evidence that may be under sloughed or fallen material,” the agency said.
“The second remote control for the shearer has not been located, nor have any additional methane detectors been found.”
MSHA noted that testing was continuing on the handheld detectors collected from the site.
More than 3000 photographs have been logged by MSHA as of this week, and investigators have compiled 183 separate documents related to the Raleigh County operation.
Those documents do not include individual data sheets or record books.
Once the headgate 22 section and tailgate 22 section are dewatered, additional rock dust samples will be taken underground.
To date, more than 1800 samples have been collected.
Finally, electrical testing is still being performed on the longwall shearer and cable components. The underground evaluation is also still ongoing by the flame and forces team.
MSHA did not indicate when it would provide another progress update, but it has been consistently updating its website as more details on the mine and explosion are made available.
That includes the Part 50 audit investigators began work on recently which it said unveiled 20 events at the operation that were not reported to MSHA as required by federal law.
In related UBB news, an MSHA official said this week that methane gas may be bubbling from a flooded area of the southern West Virginia mine.
According to the Associated Press, agency coal administrator Kevin Stricklin said that water in the flooded areas, near where nine workers were found, measures several feet.
While he did note that the bubbling water probably signaled a methane presence, coal seam gas is frequently encountered and the April 5 explosion may not have begun in that location.
Keep watching IN for more information on the UBB explosion and investigation as it becomes available.
