DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
DISTRICT 9
Accident Investigation Report
(Underground Coal Mine)
Fatal Fall of Rib Accident
Bear Canyon #1 (ID No. 42-01697)
C.W. Mining Co. (Co-op Mine)
Huntington, Emery County, Utah
July 15, 1999
by
Fred L. Marietti
Coal Mine Safety and Health Inspector, Electrical
Carl H. Schmuck
Coal Mine Safety and Health Mining Engineer
Originating Office - Mine Safety and Health Administration
Coal Mine Safety and Health, District 9
P.O. Box 25367, Denver, Colorado 80225-0367
John A. Kuzar, District Manager
GENERAL INFORMATION
Bear Canyon #1 mine is an underground coal mine, located nine miles northwest of Huntington, Emery County, Utah, adjacent to State Highway 31. The mine opened in 1982 and operated until it was idled in 1995. Operations resumed in the 3rd West Bleeder Section in April, 1999. The mine is owned and operated by C.W. Mining Company.Bear Canyon #1 mine uses the room-and-pillar method to extract coal from the Blind Canyon seam. The mine currently has one active development section that uses a remote-controlled Joy 14CM15 continuous mining machine, Joy shuttle cars, a Lee Norse TD1-43 single-boom roof bolting machine and belt haulage.
The mine employs 64 underground miners and 23 surface employees, producing an average of 700 tons of coal per day. The mine operates seven days per week with two ten-hour production shifts and one ten-hour maintenance shift per day.
Mine ventilation is provided by a Jeffrey Aerodyne fan that exhausts 81,650 cfm of air at 0.8 inches water gage. Negligible amounts of methane are liberated.
The Bear Canyon #1 mine is accessed through four entries driven into the Blind Canyon coal seam, which ranges from 8 to 19 feet thick. Typical mining height on the 3rd West Bleeder Section, where the fatal accident occurred, ranged from 7 to 9 feet within the upper portion of the Blind Canyon coal seam. Mine workings in the Tank coal seam above and the Hiawatha coal seam below do not project into the area where the accident occurred.
The 3rd West Bleeder entries were being mined to provide ventilation access to the pillar retreat section where coal pillars would be extracted from the previously developed 3rd West North entries. The 3rd West Bleeder Section is a three entry system that is developed adjacent to and between a fault, locally referred to as the Blind Canyon Fault, and the pillars that would be extracted during retreat mining.
The last regular safety and health inspection at this mine was completed by the Mine Safety and Health Administration on June 1, 1999.
The principal officials at the mine are:
Ken Defa...................................................Superintendent
Cyril Jackson..............................................Safety Director
DESCRIPTION OF ACCIDENT
On Thursday, July 15, 1999, Chris Peterson, section foreman, proceeded underground with his crew at approximately 3:00 p.m. to the 3rd West Bleeder Section (MMU 004) to begin mining coal. He assigned his seven crew members to their tasks for the shift. The continuous mining machine was in the No. 14 crosscut at the last row of bolts. He told Alejandro Medina, continuous mining machine operator (victim), and Miguel Sanchez Cruz, miner helper (injured), to clean up the crosscut and then move to the No. 2 Bleeder entry face.Peterson went to the No. 2 Bleeder entry to see what had to be done to start there. Coal had to be pushed in the face and he assigned Melecio Castro Castro, scoop operator, to push the coal on the roadway into the bolted face according to the cleanup plan, which required cleanup after the place was bolted.
Peterson came back to No. 14 crosscut where the continuous mining machine crew, Medina and Cruz, had cleaned up and cut 15 feet past the unsupported intersection, creating a hazard. He sent Medina and Cruz with the continuous mining machine to No. 2 Bleeder entry to mine. Peterson then instructed the roof bolter operator to install roof bolts in the No. 3 Bleeder entry to the No. 14 crosscut to abate the violation.
Medina and Cruz, started mining in the No. 2 Bleeder entry and had advanced the cut about 30 feet when the roof and ribs started to work. The roof failed and fell to the mine floor. They stopped mining further into the entry and ran outby. Peterson told them to clean up the fallen material and then go to No. 13 crosscut in No. 3 Bleeder entry. Cruz said they did not cleanup, but moved to No. 13 crosscut in No. 3 Bleeder entry to mine where the fatal accident later occurred.
Medina and Cruz started mining in the No. 13 crosscut in No. 3 Bleeder entry. Peterson went to work on a shuttle car that had broken down nearby and was pulled into No. 12 crosscut to clear the roadway. The other shuttle car ran over an electrical cable laying in the No. 3 Bleeder entry, which provided power to the roof bolting machine. This tripped the circuit breaker and power to the roof bolting machine. Peterson said someone told him about the damaged cable. He told them to pull the damaged part of the cable outby, out of the way. Peterson then left the section in the truck to go check the belt scale outby.
At approximately 11:00 p.m., Medina and Cruz finished advancing the cut on the left side of No. 13 crosscut and were backing the machine out to move over to the right side for the clean-up pass. Cruz was pulling the cable back out of the machine's way while Medina operated the continuous mining machine with the remote control. Cruz was six feet outby Medina with his back to the right rib. Abel Olivas Payan, roof bolting machine operator, came up behind Cruz to help with the miner cable. Victor Zavagoza Cabrera, an additional miner helper, was around the corner in No. 3 Bleeder entry. Valentin Acosta Lozoya was operating the standard-side shuttle car, which was still operational. At about 11:05 p.m., Lozoya drove into No. 3 Bleeder entry and around the corner into the No. 13 crosscut. The shuttle car cab was on the right side which allowed Lozoya to see the rib fail and roll out onto Medina and Cruz.
Lozoya, Cruz, and Cabrera said there was no warning before the rib failed. A large piece of coal rib about 13 feet long, 5 feet high, and 3 feet thick hit Medina in the back, pushing him to the floor and completely covering him causing fatal injuries. A piece of the rib about 22 inches long, 40 inches high and 21 inches thick hit Cruz in the back knocking him to the floor and into Payan. Payan was also knocked to the floor, but was not injured.
Payan, Cabrera and Lozoya pulled the coal off Cruz's back and lower legs, and then administered first aid. They called to Medina but there was no response. They tried to pull the coal off Medina but could not move it. Lozoya ran to the phone in the kitchen at the feeder breaker to call outside for help. He passed Alberto Duran, shuttle car operator, and Castro. He told them to find Rodrigo Rodriquez, graveyard foreman. Rodriquez had come into the mine with his crew of five miners at about 10:00 p.m. and was working outby on stoppings in the belt entry. Lozoya called outside and reported the accident. Duran and Castro encountered Rodriquez. Rodriquez told Castro to bring the scoop to the accident site and then went with Duran to the accident site. Rodriquez told Payan, who was at the site, to get the rest of his crew from the belt entry.
Peterson, who was outby near the portal, heard a page for him as he passed a phone. He was notified of the accident and returned to the section.
Castro placed the scoop bucket under the coal laying on top of Medina and lifted it. Rodriquez, Duran, and Cabrera pulled Medina out from under the coal. Peterson, an EMT, checked Medina for vital signs and stated that there were none.
Rodriquez, Duran, and Cabrera took Cruz to the kitchen, put him in a truck, and transported him outside where he was taken by an ambulance crew to Castleview Hospital in Price, Utah, examined and released. The doctor's work release stated that Cruz had contusions and could return to modified work on July 25, 1999, with restrictions of not more than six hours per day.
Shane Stoddard, production foreman, arrived at the section kitchen as Medina was being brought out. Medina was transported outside in Stoddard's truck. An ambulance and EMT's arrived at the mine at 11:43 p.m. and ran a defibrilator test on Medina, which showed no signs of life. Medina was placed in an ambulance and transported to Castleview Hospital, arriving at 1:05 a.m., July 16, 1999. Medina was then taken to the mortuary where he was pronounced dead by the County Coroner at 2:25 a.m.
INVESTIGATION OF THE ACCIDENT
The accident investigation began on July 16, 1999, when Robert Baker (MSHA Coal Mine Safety & Health Inspector - Castle Dale Field Office) issued 103(k) Order No. 7633274 to ensure the safety of the miners until an investigation could be conducted. Fred L. Marietti (Coal Mine Safety & Health Inspector, Electrical - Price Field Office) was appointed team leader. Marietti and John R. Turner (Education & Training Specialist, Castle Dale, UT) went underground to the accident site on July 16, 1999. Turner provided Spanish language translation support. After visiting the accident site, Marietti and Turner scheduled interviews for the next day when the complete investigation team would be available.The MSHA accident investigation team was on site the morning of July 17, 1999, after traveling from various locations across the country. The team consisted of: Fred L. Marietti, William M. Taylor (Supervisory CMI, Price, UT), John R. Turner, Carl H. Schmuck (Mining Engineer, Roof Control Group, District 9), William Crocco (Senior Mining Engineer, Division of Safety), Joseph A. Cybulski (Supervisory Mining Engineer, Technical Support, Pittsburgh, PA), and William J. Gray (Mining Engineer, Technical Support, Triadlephia, WV).
A briefing for the MSHA investigation team was conducted by Marietti and Taylor at the MSHA Field Office in Price, UT, prior to visiting the mine on July 17, 1999. The team arrived at the mine office at approximately 9:00 am. After a short conference with mine personnel, the team divided into two groups. Fred Marietti and John Turner conducted interviews of the mining crew members in the presence of Ron Tucker, the miner's representative. The other group, Taylor, Gray, Schmuck, Crocco and Cybulski went underground to the accident site with Ken Defa, Randy Defa, and Allen Weaver from the company.
The underground group examined the accident site, and other work sites that were active on the shift when the accident occurred and the shift prior to the accident. In addition, an examination of the working section where the accident occurred was initiated. The interview group conducted interviews with most of the miners on the crew and scheduled interviews with crew supervisors and the remaining miners for Monday, July 19, 1999.
The investigation team met at the Price Field Office, on July 18, 1999, to review what had been accomplished and to coordinate further activities to complete the investigation. The team returned to the mine site on July 19, 1999, and again divided into two groups. One group returned to the underground accident site. The other group completed the interviews.
PHYSICAL FACTORS
Geologic FactorsThe Blind Canyon coal seam can be up to 19 feet thick with a thin shale layer in the upper portion of the seam. The overburden above the seam has a maximum depth of 2000 feet, as reported in the approved roof control plan of December 8, 1998. The immediate roof above the coal usually consists of �-foot of mudstone, shale and/or clay. A sandstone layer, with a thickness of 80 to 120 feet lies above the immediate roof. The immediate floor beneath the coal also consists of �-foot of shale or clay. A sandstone layer, with thickness of 60 to 90 feet, lies below the immediate floor.
Geologic conditions in the 3rd West Bleeder Section consisted of an overburden depth of approximately 1200 feet. The typical mining height on the section was 7 to 9 feet within the upper portion of the Blind Canyon coal seam. The immediate roof above the coal in the section was observed to be thicker than average. Observations of roof fall material and brow separation in the 2nd and 3rd Bleeder entries indicated that the immediate roof was 18 to 36 inches thick.
A thin shale layer, noted in the typical columnar section of mine strata in the roof control plan, was present in the coal ribs in the 3rd West Bleeder entries, including the fatal accident site. As observed during the accident investigation, this shale layer did impact the condition of the ribs. The location of this layer within the mining horizon contributed to the type and severity of rib deterioration. Rib deterioration appeared to initiate and become more severe near the shale layer. When the shale layer was near the middle of the mining horizon, the ribline usually appeared more fractured, often resulting in an overhanging rib condition. A shale layer nearer the floor usually resulted in taller slabs or sheets of loose rib material. The location of the shale layer changed in the section and even divided to form two layers at some points. The shale layer was located about 42 inches from the mine floor and was several inches thick at the accident site.
A fault, locally referred to as the Blind Canyon Fault, forms the western limit of mining for the Bear Canyon #1 mine. The No. 1 Bleeder entry of the 3rd West Bleeder Section is in close proximity to this fault. Water was observed dripping from the roof and bolt holes in this entry from crosscut Nos. 10 to 11. This was the only area on the section where water was observed dripping from the roof.
Mining Factors
Pillar sizes ranged from 60 by 60 feet to 170 by 100 feet in the 3rd West Bleeder Section and in the 3rd West North Mains, located adjacent to the 3rd West Bleeder Section. The maximum entry, room, and crosscut width listed in the approved roof control plan was 20 feet. Three locations on the 3rd West Bleeder Section were observed to have mined widths in excess of 21 feet for a distance of 17, 45, and 48 feet respectively.
Primary roof support installed on the 3rd West Bleeder Section consisted of 6-foot long, 3/4-inch diameter, grade 60, fully-grouted rebar and 6-inch by 6-inch bearing plates. The typical bolt pattern observed on the section consisted of four bolts in each row across the entry with a row of bolts every five feet or less along an entry or crosscut. The minimum roof bolting pattern listed in the approved roof control plan allows a maximum spacing of five feet between bolt rows, five feet between bolts in the same row, and five feet from bolt to rib. The maximum bolt-to-rib spacing was exceeded in three locations on the 3rd West Bleeder Section for a distance of 12, 38 and 48 feet respectively.
Title 30, Code of Federal Regulations, Section 75.202(a) requires that ribs where persons work or travel shall be supported or otherwise controlled to protect persons from hazards. Loose ribs were scaled at several locations on the 3rd West Bleeder Section during the course of the accident investigation. An overhanging rib was observed along the right rib from the accident site outby to the pillar corner. No installed rib support was observed on the section.
The overhanging rib condition at No. 13 crosscut had a depth of 1 to 2 feet. The overhanging rib appeared to be due in part to uneven mining of the ribline. Marks from the continuous mining machine cutting drum were visible on the lower portion of the rib and created a stepped profile as more of the rib was mined as the cutting drum was lowered. Rock dust was present on the lower portion of the rib indicating that this condition existed prior to the accident.
A Lee Norse TD1-43, single-boom, roof bolting machine was used to install roof bolts on the 3rd West Bleeder Section. The typical spacing between bolt rows on the section was 54 inches. A roof fall, experienced while mining in No. 2 Bleeder entry prior to the accident, had fallen up to the last row of installed support.
Other Factors
1. Training on hazard recognition and the requirements of the roof control plan were inadequate. This was determined through interviews with miners and supervisors. Inadequate preshift and onshift examinations, which did not record obvious roof and other hazards, also indicate a lack of training in these areas.
2. A communication problem existed between Spanish and English speaking supervisors and miners at the mine. This language barrier caused safety problems in completely understanding work assignments and the associated hazards for the Spanish speaking Hispanic miners. One English speaking section foreman stated that he did not speak very good Spanish, but that he got his points across. The miner helper injured in the accident spoke no English. The additional miner helper and one shuttle car operator on this crew also spoke no English.
CONCLUSION
Loose, hazardous rib conditions, that were not taken down (barred down) or supported at the accident site, were the direct cause of the fatal accident on July 15, 1999. The following conditions were directly related to the rib failure:1. Geologic conditions in the area contributed to the deterioration of the ribs. Rib deterioration from stress was observed at the accident site and throughout the section. Stress resulted from the depth of cover (1200 feet) and the proximity of a fault.
The rock (shale) layer present in the coal appeared to intensify the loose rib conditions. Rib deterioration was observed to become more severe near the shale layer. This shale layer was located about 42 inches from the mine floor at the accident site, which contributed to an overhanging rib condition.
2. Mining practices at the accident site contributed to the overhanging rib condition. Uneven mining of the rib was evident from marks made by the continuous mining machine cutting drum on the lower portion of the right rib. A stepped profile was mined as the cutting drum was lowered.
The ribs on the mining section were also being undercut by the scoop bucket being pushed into the ribs, as loose coal was cleaned up after mining.
3. Inadequate examinations of the work areas contributed to the fatal accident. Records of the pre-shift and on-shift examinations for the 3rd West Bleeder Section, including the accident site, did not indicate the existence of hazards that were evident throughout the section.
A review of the pre-shift and on-shift examination records from March 30 through July 15, 1999, found that very few hazards were entered in the record. None of the hazardous conditions observed during the accident investigation were noted in the records. An adequate examination of the work area and proper record keeping would allow hazards to be recognized and corrected.
4. Interviews with miners and supervisors indicated that there was inadequate training on hazard recognition and the requirements of the roof control plan.
5. Communication issues, such as communication problems between English and Spanish speaking miners and a lack of mining experience for some employees, appeared to affect complete understanding of work assignments and the associated hazards.
ENFORCEMENT ACTIONS
1. Section 103(k) Order No. 7633274, dated July 16, 1999, was issued to ensure the safety of the miners until an investigation could be conducted.2. Section 104(d)(1) Order No. 7611452, dated July 16, 1999, was issued for a violation of 30 CFR 75.202(a). The rib that caused the fatal injury was not being supported or otherwise controlled to prevent this fatal accident.
3. Section 104(d)(1) Order No. 7611456, dated July 16, 1999, was issued for a violation of 30 CFR 75.360(a)(1). Adequate pre-shift examinations were not being conducted to address the rib conditions and other hazards in the section.
4. Section 104(d)(1) Order No.7611457, dated July 16, 1999, was issued for a violation of 75.362(a)(1). Adequate on-shift examinations were not being conducted to address rib conditions and other hazards in the section.
5. Section 104(d)(1) Order No. 7611462, dated July 19,1999, was issued for a violation of 75.203(a). Poor mining practices in the section created conditions that increased the likelihood that the ribs would fail and cause this fatal injury.
Submitted by:
Fred L. Marietti - Coal Mine Safety and Health Inspector, Electrical
Carl H. Schmuck - Mining Engineer
Approved by:
Irvin T. Hooker
Assistant District Manager for
Enforcement Programs
John A. Kuzar
District Manager
Related Fatal Alert Bulletin: 
FAB99C18
APPENDIX
The investigation was conducted by the Mine Safety and Health Administration and those persons furnishing information and/or present during the investigation were:C.W. Mining Co. (Co-op Mine) Officials/Employees/Consultant
Ken Defa.........................................................................Superintendent
Randy Defa......................................................................Maintenance Foreman
Shane Stoddard................................................................Production Foreman
Chris Peterson..................................................................Section Foreman
Rodney Anderson.............................................................Section Foreman
Valentin Acosta Lozoya....................................................Standard Shuttle Car Operator
Melecio Castro Castro .....................................................Scoop Operator
Abel Olivas Payan.............................................................Roof Bolter Operator
Victor Zavagoza Cabrera..................................................Miner Helper
Miguel Sanchez Cruz.........................................................Miner Helper
Jared Stephens..................................................................Mechanic Electrician
Joel A. Strid......................................................................NSA Engineering Inc, Consultant
International Association of United Workers
Ron Tucker......................................................................Miners' Representative Utah State Labor Commission
Ron Parkin.......................................................................Representative Mine Safety & Health Administration
Fred L. Marietti...............................................................Coal Mine Safety & Health Inspector, Electrical
John R.Turner..................................................................Education & Training Specialist
Carl H. Schmuck.............................................................Mining Engineer
William M. Taylor............................................................Supervisory Coal Mine Safety & Health Inspector
William Crocco...............................................................Division of Safety, Senior Mining Engineer
Joseph A. Cybulski.........................................................Technical Support, Supervisory Mining Engineer,
Roof Control Division
William J. Gray...............................................................Technical Support, Mining Engineer,
Roof Control Division
