An employee was struck by a slab of rock that measured approximately 8 inches to 12 inches thick by 50 to 70 inches wide by 74 inches long. The roof fall occurred at the 34 Main between crosscut 1 North 4 and 1 North 5.
W Thomas Mackall: 1 recorded fatality controller
Watch this controller
Email me when a new MSHA incident is filed at any mine W Thomas Mackall controls.
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This rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.ⓘ
A Section 107(a) order removes miners from an area when an inspector finds an imminent danger. Each order is lifted once the condition is corrected, so this counts orders issued, not orders now in effect.ⓘ
Differences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.ⓘ
Shares are computed over citations that carry the MSHA gravity and negligence coding; a small share of records are uncoded.ⓘ
This rate is reportable injury cases per 100 full-time-equivalent workers per year, computed as 200,000 times cases divided by MSHA operator-reported employee-hours. Cases are injuries MSHA graded degree 01 through 07; accident-only events that hurt no one are excluded, and so are contractor injuries, whose hours do not attach to a single mine. Rates begin in 2000, when quarterly employment reporting starts, and are withheld below 20,000 hours in a year.| Year | total case rate | days-away | fatal |
|---|---|---|---|
| 2026 * | 0.00 | 0.00 | 0.000 |
| 2025 | 1.51 | 1.51 | 0.000 |
| 2024 | 1.57 | 1.57 | 0.000 |
| 2023 | 0.00 | 0.00 | 0.000 |
| 2022 | 0.00 | 0.00 | 0.000 |
| 2021 | 0.00 | 0.00 | 0.000 |
| 2020 | 3.62 | 3.62 | 0.000 |
| 2019 | 1.24 | 0.00 | 0.000 |
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A sample is a point in time compliance measurement, not an individual exposure history. These figures describe MSHA sampling records and do not establish causation or personal dose.Respirable coal dust
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Respirable coal dust and silica figures cover coal facilities. Dust compliance is measured against the current 1.5 mg/m3 standard; samples predating the 2014 standard are included, so compliance rates are a coarse historical signal.
Last sampled: 2016-12-29, 9 years ago
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Respirable coal dust and silica figures cover coal facilities. Dust compliance is measured against the current 1.5 mg/m3 standard; samples predating the 2014 standard are included, so compliance rates are a coarse historical signal.ⓘ
The excessive concentration value (ECV) is MSHA's own per-sample enforcement threshold, which builds in measurement uncertainty; a sample over its ECV can trigger a citation. The count covers only samples MSHA assigned an ECV.- AUGER OPERATOR1,110
- MOBILE BRIDGE OPERATOR268
- ROOF BOLTER (TWIN HEAD) (RETURN SIDE)148
Silica (quartz)
Last sampled: 2015-01-26, 11 years ago- AUGER OPERATOR70
- ROOF BOLTER (TWIN HEAD) (RETURN SIDE)1
Noise
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The share counts noise samples whose measured dose exceeded the 90 dBA permissible exposure limit. It describes the sampled workplace, not what reached the miner's ear: hearing conservation programs and the hearing protection worn during the shift are recorded separately and are not reflected here.
Last sampled: 2017-01-05, 9 years ago
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The share counts noise samples whose measured dose exceeded the 90 dBA permissible exposure limit. It describes the sampled workplace, not what reached the miner's ear: hearing conservation programs and the hearing protection worn during the shift are recorded separately and are not reflected here.- MOBILE BRIDGE OPERATOR42
- HIGHLIFT OPERATOR/FRONT END LOADER40
- ROOF BOLTER (TWIN HEAD) (INTAKE SIDE)26
Metal and nonmetal contaminants (personal samples)
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Many samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.
Last sampled: 2026-05-13
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Many samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.- Diesel particulate (total carbon)13632 over
- TC as EC @ 3502914 over
- TCarbon @ 3502914 over
- Quartz, respirable, >1% Qtz459 over
Area samples (mill and shop air)
Last sampled: 2026-04-07ⓘ
Contesting a citation before the Federal Mine Safety and Health Review Commission is a lawful right. These figures state the public outcomes of that process, from MSHA's Contested Violations file.- Settled 63 · 100%
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Counts a Significant & Substantial citation as surviving when a settlement or judge's decision kept the designation, or the contest was dismissed or defaulted so the citation stands as issued. Vacated and withdrawn citations, and settlements that removed the designation, count against.ⓘ
A reduction or dismissal at the Commission is a lawful outcome of contesting a proposed penalty. Figures are the proposed amount and the amount upheld in the docket's decision.| Docket | Decision | Judge | Year | Proposed / upheld |
|---|---|---|---|---|
| LAKE 2012-732M | Settlement | Miller | 2013 | $140K → $21K |
| LAKE 2011-366 | Settlement | Harner | 2012 | $105K → $38K |
| LAKE 2012-662 | Settlement | Lewis | 2013 | $67K → $50K |
| LAKE 2015-0503 | Settlement | Miller | 2015 | $18K → $13K |
| LAKE 2015-0056 | Settlement | Andrews | 2015 | $14K → $9K |
| LAKE 2011-1002 | Settlement | Paez | 2013 | $9K → $8K |
Top causes
- FALL OF ROOF OR BACK 1 fatality · 64 non-fatal
- HANDLING OF MATERIALS 34 non-fatal
- SLIP OR FALL OF PERSON 28 non-fatal
- HANDTOOLS (NONPOWERED) 20 non-fatal
- MACHINERY 17 non-fatal
- POWERED HAULAGE 15 non-fatal
Incident timeline
Operators under this controller
Mines on record
- Subtropolis OH
- Petersburg Mine OH
- Carroll Hollow #6 OH
- Shean Hill Mine OH
- South Mine/Washplant OH
- Davison Mine OH
- Carroll Hollow Mine OH
- Petersburg Mines OH
- Sterling North Mine OH
- Commercial Mine OH
- K Mine OH
- Clark Mine PA
- Fullerton PA
- Gavers Mine OH
Fatalities under this controller
1 recordedWhere W Thomas Mackall stands on silica, penalties, and injury rate
MSHA's standard limits respirable silica to 50 micrograms per cubic metre, but MSHA publishes dust and quartz as separate files and never the silica figure itself. We derive it per sample, score it against the limit, and set the operator's injury rate against a benchmark built from the full MSHA operator record. With the 26-year penalty trail, contest posture, and fatality history. Delivered as a PDF with the underlying data as CSV.
The federal record itself stays free on this site. What costs money, and why.