Mining Incidents

Knoxville Mine Metal/Non-Metal

NR Hamm Quarry LLC · Underground
Controlled by Summit Materials LLC
Knoxville, Marion County, IA  ·  Abandoned
MSHA Mine ID: 1302217

Knoxville Mine has $501K in proposed MSHA penalties and $0 outstanding across 31 contested dockets, plus health sampling and the full incident record.

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Fatalities
1
Total incidents
30
Years on record
1998–2025
Latest incident
Jun 2025
Compliance record
MSHA citations since 2000
798
citations
213
significant & substantial
$501,238
proposed penalties
$454,442
paid to date
91% of proposed penalties paid to date, a $46,796 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2000
214
inspections on record
5,186
inspection hours
15.4
citations per 100 inspection hours
This rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.
798 citations across 5,186 inspection hours.
Source: MSHA inspections data, updated weekly.

Knoxville Mine has $501K in proposed MSHA penalties and $0 outstanding across 31 contested dockets.

Penalty disposition
Differences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$501K
proposed penalties
$454K
current assessed
$454K
paid to date
$0
outstanding
780 assessments are final orders; 31 contested dockets.
As of the most recent assessment on 2025-12-16.
Source: MSHA assessed-violations and conference/litigation data, updated weekly.
Quarterly safety rates
Citations per million reported employee-hours. Rates begin in 2000, when MSHA's quarterly employment data starts; earlier incidents are counted but cannot be rate-adjusted. Quarters under 100,000 reported hours are greyed: too few hours for a stable rate.
Citations per million employee-hours, as reported to MSHA
Quarter Hours worked Citations S&S Per 1M hrs
2025 Q4 3,851 8 2 2077.4
2025 Q3 6,431 1 0 155.5
2025 Q2 15,752 5 0 317.4
2025 Q1 12,690 6 2 472.8
2024 Q4 13,934 0 0 0.0
2024 Q3 12,514 3 1 239.7
2024 Q2 12,903 0 0 0.0
2024 Q1 12,676 1 1 78.9
Show 96 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2023 Q4 12,236 2 0 163.5
2023 Q3 12,587 5 0 397.2
2023 Q2 13,876 7 3 504.5
2023 Q1 13,941 2 0 143.5
2022 Q4 12,551 3 0 239.0
2022 Q3 12,867 1 0 77.7
2022 Q2 13,583 3 0 220.9
2022 Q1 11,132 8 0 718.6
2021 Q4 11,199 12 1 1071.5
2021 Q3 11,855 13 4 1096.6
2021 Q2 13,150 7 0 532.3
2021 Q1 12,845 8 0 622.8
2020 Q4 13,497 12 3 889.1
2020 Q3 15,874 10 1 630.0
2020 Q2 15,568 10 1 642.3
2020 Q1 12,714 7 2 550.6
2019 Q4 12,464 17 3 1363.9
2019 Q3 14,019 12 2 856.0
2019 Q2 13,338 18 4 1349.5
2019 Q1 8,393 7 1 834.0
2018 Q4 9,835 18 7 1830.2
2018 Q3 13,158 15 5 1140.0
2018 Q2 15,073 14 5 928.8
2018 Q1 9,613 30 8 3120.8
2017 Q4 11,408 5 2 438.3
2017 Q3 12,407 6 3 483.6
2017 Q2 14,025 5 0 356.5
2017 Q1 10,539 13 0 1233.5
2016 Q4 13,205 10 3 757.3
2016 Q3 12,931 8 3 618.7
2016 Q2 13,613 4 1 293.8
2016 Q1 11,957 4 0 334.5
2015 Q4 12,099 18 8 1487.7
2015 Q3 14,091 17 4 1206.4
2015 Q2 15,167 14 5 923.1
2015 Q1 12,067 18 3 1491.7
2014 Q4 14,756 8 2 542.2
2014 Q3 16,051 7 2 436.1
2014 Q2 13,883 9 2 648.3
2014 Q1 11,528 4 1 347.0
2013 Q4 13,283 10 1 752.8
2013 Q3 14,727 10 4 679.0
2013 Q2 13,797 5 1 362.4
2013 Q1 10,255 3 0 292.5
2012 Q4 13,462 7 1 520.0
2012 Q3 13,422 3 0 223.5
2012 Q2 12,868 2 2 155.4
2012 Q1 10,218 5 1 489.3
2011 Q4 11,612 3 2 258.4
2011 Q3 13,779 1 0 72.6
2011 Q2 14,898 3 1 201.4
2011 Q1 7,884 3 1 380.5
2010 Q4 8,162 8 6 980.2
2010 Q3 9,325 5 3 536.2
2010 Q2 9,447 5 1 529.3
2010 Q1 8,182 6 6 733.3
2009 Q4 7,613 2 1 262.7
2009 Q3 8,871 8 6 901.8
2009 Q2 8,735 5 0 572.4
2009 Q1 7,080 3 0 423.7
2008 Q4 7,829 12 1 1532.8
2008 Q3 8,365 8 2 956.4
2008 Q2 8,378 1 1 119.4
2008 Q1 7,081 6 0 847.3
2007 Q4 7,493 8 1 1067.7
2007 Q3 6,905 13 6 1882.7
2007 Q2 7,229 20 5 2766.6
2007 Q1 6,464 10 2 1547.0
2006 Q4 5,685 5 3 879.5
2006 Q3 6,743 3 0 444.9
2006 Q2 7,037 10 3 1421.1
2006 Q1 6,460 1 0 154.8
2005 Q4 6,856 8 4 1166.9
2005 Q3 7,434 11 4 1479.7
2005 Q2 6,388 16 8 2504.7
2005 Q1 5,477 10 3 1825.8
2004 Q4 5,825 7 2 1201.7
2004 Q3 6,158 5 1 812.0
2004 Q2 6,347 18 4 2836.0
2004 Q1 5,324 7 0 1314.8
2003 Q4 6,312 9 3 1425.9
2003 Q3 5,531 6 0 1084.8
2003 Q2 5,492 5 1 910.4
2003 Q1 5,238 17 3 3245.5
2002 Q4 6,074 6 1 987.8
2002 Q3 5,087 1 0 196.6
2002 Q2 5,646 3 0 531.3
2002 Q1 4,616 5 1 1083.2
2001 Q4 3,999 7 0 1750.4
2001 Q3 4,575 14 6 3060.1
2001 Q2 4,815 4 3 830.7
2001 Q1 3,792 8 4 2109.7
2000 Q4 3,751 1 1 266.6
2000 Q3 4,046 9 5 2224.4
2000 Q2 4,035 7 3 1734.8
2000 Q1 3,187 5 0 1568.9

Fatalities at this mine

1 recorded
September 29, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler Fatality · POWERED HAULAGE
Bruening Rock Products Inc · Caught in, under or between (Not Elsewhere Classified)

EMPLOYEE APPARENTLY ATTEMPTED TO EXIT MACHINE TO THE RIGHT UNDER THE BOOM. WHILE EXITING, THE EMPLOYEE'S HIP ENGAGED THE BOOM LOWER CONTROL, CAUSING THE BOOM TO LOWER AND CRUSH EMPLOYEE'S TORS O, CAUSING FATAL INTERNAL INJURIES.

Reportable incidents

29 on file (excluding fatalities above)

2025 · 3 incidents

June 25, 2025 IA · Metal/Non-Metal FALL OF ROOF OR BACK
NR Hamm Quarry LLC · Accident type, without injuries

An unplanned cave-in / release of material occurred underground during the second shift. During the second shift employees were loading shot rock and transporting to surface storage area when employees heard material falling and an accumulation of dust appeared in their area.

June 25, 2025 IA · Metal/Non-Metal miner, nec FALL OF ROOF OR BACK
NR Hamm Quarry LLC · Struck by... (Not Elsewhere Classified)

The underground mine had a cave-in and the employee is experiencing ringing in the left ear and headaches caused by the loud noise and air pressure.

June 25, 2025 IA · Metal/Non-Metal miner, nec FALL OF ROOF OR BACK
NR Hamm Quarry LLC · Struck by... (Not Elsewhere Classified)

The underground mine had a cave-in and employee is experiencing ringing of the left ear and headaches caused by the loud noise and air pressure.

2020 · 3 incidents

November 12, 2020 IA · Metal/Non-Metal blaster, shooter, shotfirer, explosive worker, powder gang/monkey FALL OF ROOF OR BACK
Bruening Rock Products Inc · Struck by falling object

Employee was cleaning out a lifter hole by hand when some rock sluffed off the face and struck them in the back. Result was fractured ribs.

October 7, 2020 IA · Metal/Non-Metal haul/off road/coal/ore/pit/quarry/rock/rubber tire truck driver, transportation truck driver POWERED HAULAGE
Bruening Rock Products Inc · Struck against a moving object

Employee was backing up to dump, upon raising box, the rubber pads/bushing pulled apart from the suspension on the rear driver's side wheels causing the weight to shift on the box and tipping the truck over

September 15, 2020 IA · Metal/Non-Metal haul/off road/coal/ore/pit/quarry/rock/rubber tire truck driver, transportation truck driver SLIP OR FALL OF PERSON
Bruening Rock Products Inc · Over-exertion (Not Elsewhere Classified)

Employee was getting out of a haul truck with left hand on handrail behind door frame and right hand on door. Went to get down and turned body away from truck releasing right hand from the door and upon going to step down did not release left hand and dropped dislocating shoulder.

2018 · 1 incident

December 13, 2018 IA · Metal/Non-Metal miner, prospector, nec MACHINERY
Bruening Rock Products Inc · Caught in, under or between running or meshing objects

The crushing plant had gotten plugged. After getting the plant unplugged EE was helping up a access door back on when EE's coat was snagged by the conveyor belt. EE's arm was pulled into the conveyor and tail pulley.

2007 · 1 incident

February 16, 2007 IA · Metal/Non-Metal bull gang foreman, labor foreman, leadman, section foreman, shift boss HANDLING OF MATERIALS
Bruening Rock Products Inc · Over-exertion in lifting objects

Employee was fixing/removing a guard on a tail section of plant. He stood up lifting guard and twisted right knee.

2000 · 2 incidents

May 15, 2000 IA · Metal/Non-Metal FALL OF ROOF OR BACK
Bruening Rock Products Inc · Accident type, without injuries

ROOF FALL IN ABANDON HEADING NO DAMAGE OR INJURYFILED 30FT OF HEADING BELEIVE THE AREA ABOVE HEADING IS OLD RIVER CHANEL DUE TO WATER EROSION LOST ROOF SUPPORT NO WAY OF KNOWING THIS AREA WAS AS LARGE OTHER AREA OF MINE ARE OK

January 7, 2000 IA · Metal/Non-Metal continuous miner operator, coal mole operator HANDLING OF MATERIALS
Bruening Rock Products Inc · Over-exertion in lifting objects

EMPLOYEE WAS MOVING A P4 WILDEN DIAPHRAM PUMP OUT OF FACE AREA. HE PICKED PUMP UP WITH ONE HAND (APPROX 20LB.) AND TWISTED TO THE SIDE TO SET THE PUMP DOWN AND FELT PAIN UNDER LEFT SHOULDER B LADE AND BACK.

1999 · 12 incidents

December 13, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Over-exertion in lifting objects

EE WAS HELPING TO INSTALL 30" DIA X 10' VENTILATION TUBING (FIBERGLASS), WHILE LIFTING AND HOLDING THE TUBING IN PLACE. HE FELT PAIN BETWEEN SHOULDER BLADES.

November 27, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler MACHINERY
Bruening Rock Products Inc · Caught in, under or between a moving and a stationary object

EE WAS HELPING INSTALL ROCK BOLTS IN THE ROOF USING A ROCK DRILL AND AIR LEG. WHILE BACKING OUT OF THE HOLE JUST DRILLED THE EE PLACED HIS LEFT HAND BETWEEN THE BASE OF THE DRILL AND THE AIR L EG. THE DRILL SHIFTED PINCHING HIS LEFT RING FINGER.

November 24, 1999 IA · Metal/Non-Metal laborer, bull gang, faceman, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Absorption of radiations, caustics, toxic and noxious substances

EE WAS HELPING TO APPLY SHOT CRETE LINING TO THE TUNNEL AND EXCESS MATERIAL ACCUMULATED IN EES BOOTS WITHOUT HIS KNOWLEDGE. THE MATERIAL INFLICTED ALKALINE BURNS TO HIS ANKLE AND FEET.

November 10, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Struck by falling object

EE WAS STANDING BY RIB WITH LEFT ARM OUT STRETCHED LEANING ON ARM 2 OTHER EE'S WERE ELEVATING A SECTION OF 2" PLASTIC WATER LINE & IT SLIPPED & STRUCK EE'S OUTSTRETCHED ARM AGGRAVATING A PRE EXISTING CONDITION

October 24, 1999 IA · Metal/Non-Metal laborer, bull gang, faceman, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Over-exertion in lifting objects

EE WAS USING A SHORT HANDEL SPADE TO CLEAR ROCK AND MUD AWAY FROM THE LOADING APRON ON AN AM50 ROAD HEADER AND FELT A SHARP PAIN IN GROIN.

September 11, 1999 IA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman DISORDERS (REPEATED TRAUMA)
Bruening Rock Products Inc · Over-exertion (Not Elsewhere Classified)

EE DIAGNOSED BILATERAL CARPAL TUNNEL SYNDROME LIMITED USE BOTH HANDS

August 23, 1999 IA · Metal/Non-Metal continuous miner operator, coal mole operator ENTRAPMENT
Bruening Rock Products Inc · Caught in, under or between (Not Elsewhere Classified)

AN UNPLANNED ROOF FALL OCCURED IN THE LEFT FACE OF THE TOP HEADING. THE FALL WAS APPROX 25 FT IN LENGTH AND RANGED IN THICKNESS FROM 5 FT TO 3 FT. THE ROOF FALL BRIDGED ACROSS THE OPERATOR CAN OPY ENTRAPPING THE OPERATOR 25 TO 30 MIN. THE EEWAS REMOVED, NO APPARENT INJURY.

August 23, 1999 IA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman OTHER
Bruening Rock Products Inc · Bodily reaction, (Not Elsewhere Classified)

EE WAS SITTING IN OFFICE FOR 10-15 MINUTES AND BACK BECAME SORE. WORKED ON USUAL ROUTINE FIRST HALF OF SHIFT.

May 11, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler MACHINERY
Bruening Rock Products Inc · Over-exertion (Not Elsewhere Classified)

EE WAS DRILLING FLOOR WITH A SINKING HAMMER. HE PULLED THE DRILL AND STEEL UP TO MOVE TO ANOTHER HOLE LOCATION AND FELT A SHARP PAIN DOWN HIS RIGHT ARM CHEST AND SIDE.

May 3, 1999 IA · Metal/Non-Metal bull gang foreman, labor foreman, leadman, section foreman, shift boss POWERED HAULAGE
Bruening Rock Products Inc · Struck by... (Not Elsewhere Classified)

EE WAS SUPERVISING THE REPOSITIONING OF A CEMENT PUMP WITH AN END LOADER AND CHAIN. HE RESTED HIS ELFT HAND ON THE BUCKET CLOSE TO WHERE THE CHAIN WAS ATTACVHED. THE CHAIN SLIPPED UNDER LOAD A ND SHIFTED ACROSS RING FINGER ON LEFT HAND, FRACTURING 1ST BONE AND INFLICTING A LACERATION WOUND TO THE FINGERTIP.

May 3, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Over-exertion (Not Elsewhere Classified)

EE WAS REMOVING 30" FIBERGLASS VENTILATION LINE FROM OVERHEAD. THE SECTION HE WAS REMOVING WAS ATTACHED TO SEVERAL SECTIONS WHICH FELL AFTER HE UNTIED THE WIRE SUSPENDING THE VENTLINE. EE WAS HOLDING THE VENT LINE BY A "D" RING AND WAS UNABLE TO LET GO FAST ENOUGH PULLING MUSCLES IN SHOULDER OF RIGHT ARM. STARTED MISSING WORK 5/9/99.

April 14, 1999 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Struck by... (Not Elsewhere Classified)

EMPLOYEE WAS UNLOADING A LATTICE GIRDER SECTION OUT OF A LOADER BUCKET WHEN HE SAT IT DOWN ON TEH INVERT IT SHIFTED AND STRUCK HIS RIGHT SHIN CAUSING AN ABRASION TO HIS LEG. ABRASION BECAME I NFECTED ON 4-18-99, EMPLOYEE WENT TO HOSPITAL.

1998 · 7 incidents

December 19, 1998 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler MACHINERY
Bruening Rock Products Inc · Caught in, under or between (Not Elsewhere Classified)

THE ROAD HEADER MINER HAD BEEN BACKED UP 10-12FTFROM FACE AREA AFTER CUTTING AND CLEANING MUCK OFF THE INVERT. THE FACE WAS BEING MEASURED & PAINTED FOR THE NEXT CUT CYCLE. THE OPERATOR HAD DEENEGERIZED THE CUTTER HEAD AND LOWERED THE BOOM WHICH SUPPORTS THE CUTTER DRUM. THE OPERATOR PROCEEDED TO HELP WALKING PAST THE HEAD WHICH WAS STILL ROTATING HIS RIGHT FOOT WAS CAUGHT BY A

August 24, 1998 IA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman MACHINERY
Bruening Rock Products Inc · Struck against stationary object

EE WAS CLEANING A SHOTCRETE WITH A PRESSURE WASHER. HE DISASSEMBLED THE NOZZEL AFTER CLEANING THE EXTERIOR PORTION AND ATTEMPTED TO CLEAN SMALL COMPENTS BY HOLDING THEM IN HIS LEFT HAND AND US ING THE SPRAY WAND IN HIS RIGHT HAND. HE INFLICTED A PUNCTURE WOUND TO LEFT HAND BETWEEN THUMB AND FOREFINGER.

August 14, 1998 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler FALL OF ROOF OR BACK
Bruening Rock Products Inc · Struck by falling object

EE WAS MOVING SOME AREA LIGHTING IN THE TUNNEL AND A PIECE OF ROCK WEIGHING APPROX 30-40 PDS ROLLED DOWN THE FACE AND ACROSS HIS RIGHT LEG AND FOOT, HE TWISTED AROUND AND PULLED HIS FOOT OUT F ROM UNDER ROCK RESULTING IN A SPRAIN TO HIS ANKLE

June 14, 1998 IA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman HANDLING OF MATERIALS
Bruening Rock Products Inc · Absorption of radiations, caustics, toxic and noxious substances

EE WAS ATTEMPTING TO FILL A PRESSURIZED TANK WITH ACCELERATOR AND DID NOT BLEED THE AIR PRESSURE FROM TANK BEFORE OPENING FILL COCK.

May 20, 1998 IA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman MACHINERY
Bruening Rock Products Inc · Struck by... (Not Elsewhere Classified)

EMPLOYEE WAS USING A 90 LB AIR HAMMER TO DIG A FOOTING IN ROCK. EMPLOYEE POSITIONED HAMMER TO BREAK ROCK. WHILE OPERATING HAMMER, THE BIT BOUNCED OFF THE ROCK AND LANDED ON LEFT FOOT. THE BIT PUNCTURED THE LEFT FOOT REQUIRING SUTURES.

May 13, 1998 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler HANDLING OF MATERIALS
Bruening Rock Products Inc · Struck by... (Not Elsewhere Classified)

EE WAS HELPING SET A 3 PEICE LATTICE GIRDER ASSEMBLY WHICH WAS BEING SUPPORTED BY AND END LOADER. WHILE ATTEMPTING TO SECURE THE GIRDER WITH 9 WIRE THE GIRDER SHIFTED AND STRUCK THE EE ON THE RIGHT FOREARM.

April 28, 1998 IA · Metal/Non-Metal laborer, bull gang, parts runner, roustabout, roof trimmer/scaler MACHINERY
Bruening Rock Products Inc · Over-exertion (Not Elsewhere Classified)

EE WAS CUTTING EXCESS CEMENT OFF THE SIDE WALL OF THE SLOPE USING AN AIR OPERATED HAMMER & OVER EXTENDED HIS RIGHT WRIST.

For insurers, brokers, and safety consultants

The full compliance file on Knoxville Mine

A dated report covering the 26-year penalty trail, line-item violation pattern, contest and docket posture, rate-normalized peer benchmark, and full fatality history. Delivered as a PDF with the underlying data as CSV.