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UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Metal and Nonmetal Mine Safety and Health

REPORT OF INVESTIGATION

Surface Nonmetal Mine
(Crushed Stone)

Fatal Machinery Accident

April 2, 2001

Kona Cinder & Soil, Inc.
Kona Cinder & Soil, Inc.
Oceanview, Hawaii County, Hawaii
ID No. 51-00235

Accident Investigators

Larry Larson
Supervisory Mine Safety and Health Inspector

Harvey Brooks
Mine Safety and Health Inspector

Paul Tyrna
Geologic Engineer

John Kathman
Mine Safety and Health Specialist

Originating Office
Mine Safety and Health Administration
Western District
2060 Peabody Road, Suite 610
Vacaville, CA 95687

Lee D. Ratliff, District Manager


OVERVIEW

James W. Mitchell, plant manager/bulldozer operator, age 48, was fatally injured on April 2, 2001, when a highwall collapsed and buried the dozer he was operating.

The accident occurred because mining methods that would maintain wall, bank, and slope stability were not being used.

Mitchell had 16 years mine experience, 28 weeks with this company as plant manager. There was no documentation of Mitchell having received training in accordance with 30 CFR Part 46.

GENERAL INFORMATION

The Kona Cinder & Soil Inc, a surface cinder mine, owned and operated by Charles Harlan, was located at Oceanview, Hawaii County, Hawaii. The mine was 50 miles south of Kailu-Kona Hawaii. The principal operating officials were Charles Harlan, owner, and James W. Mitchell, plant manager and equipment operator. The mine operated one, 10-hour shift a day, five days a week. Total employment was four persons.

Cinders were mined using one Caterpillar D8H bulldozer and a Case 281 front-end loader. The material was pushed to a location near the crusher and then loaded into the feeder by a front-end loader where it was crushed, screened and stockpiled. The finished material was shipped to customers by truck for use as aggregate and fill.

MSHA first became aware of this mine as a result of this accident. A regular inspection was completed in conjunction with the accident investigation.

DESCRIPTION OF ACCIDENT

On the day of the accident, James W. Mitchell (victim) reported for work at 7:00 a.m., his normal starting time. Mitchell began his normal routine of pushing material from the toe of the highwall. The material was pushed into a pile so it could be hauled from this point to the crusher located close by. Mitchell also loaded the over-the-road trucks and supplied the crusher with material throughout the morning.

At approximately 10:30 a.m., Rudy Kana, truck driver, was returning to the pit for another load when he noticed smoke coming from a pile of cinders below the highwall. Realizing the 80 to 100-foot highwall had collapsed and buried the machine and operator, he rushed to the pile. David Cahill, truck driver, arrived a few minutes later and they both began digging the cinders away from the top of the dozer. They proceeded to dig with their hands until they uncovered the victim. Once they uncovered Mitchell, they performed cardiopulmonary resuscitation until emergency personnel arrived. Mitchell was transported to a local hospital where he was pronounced dead. Death was attributed to asphyxiation.

INVESTIGATION OF THE ACCIDENT

MSHA was notified of the accident on April 3, 2001, at 9:17 a.m., by a fax from the Hawaii Tribune to William W. Wilson, assistant district manager. Charles Clark, HI-OSHA compliance officer, started an investigation on April 4, 2001. MSHA's investigation began April 10, 2001 after determining this operation was a mine. An order was issued pursuant to Section 103(k) of the Mine Act to ensure the safety of miners. MSHA conducted an inspection of the accident site, interviewed miners, and reviewed appropriate training and work procedure documents. The miners did not request, nor have a representative during the investigation.

DISCUSSION

  • As illustrated by the map shown in Appendix C, the mine was composed of an upper and lower pit connected by a ramp and separated by a graded slope of mostly loose cinders. The upper pit, in turn, is separated from a level area at the east end of the property by another ramp and graded slope composed of loose cinders. Thus, the mine is bounded by highwalls on the north, south, and west sides and a variable slope on the east side.


  • The accident occurred at the base of the north highwall about 25 feet above the lower pit floor on a narrow (15 ft wide) part of a bench that spans the northwest corner of the mine. The height of the face above the bench was estimated to be 80 to 100-feet high. The north highwall was cut into the uphill side of the regional slope and was variable in terms of height and bench configuration. The uppermost portion of the highwall, above the top bench, decreased in height, east to west, from 70 feet to just a few feet near the west end of the bench. Here, west of the "point," the upper benches had been truncated by the development of the west half of the north highwall. A travelway extended along the base of the north higwall from the 30-foot bench in the northwest corner to the "upper flats" area. Total height of the north highwall, including the lower 30-foot bench in the northwest corner, and the upper benches in the east, ranged from 55 feet to 160 feet.


  • In general, pit walls, over the last several years appear to have been developed both vertically and horizontally with no benches and near-vertical faces. Heights of up to 75 feet for a single face were observed in the north highwall. Older benches, including the upper benches on the north highwall and the remnant benches on the west highwall had been removed by recent production. Unfortunately, no past or current mine maps were available, resulting in some ambiguity about the structural evolution of the highwalls.


  • The fallen material consisted of unconsolidated cinders, with gray cinders overlying red. It appeared, however, that red cinders were being excavated at the accident site, as evidenced by the material being pushed down the ramp to the mixing point in the lower pit. A photograph take a few days prior to the accident shows the highwall was undercut. Thus, some of the red cinders beneath the fallen material may have been part of normal production. The fallen cinders spanned the entire width of the lower bench and spilled into the lower pit. The total volume of the fall was estimated to be in excess of 500 cubic yards. The lower bench, where the fall occurred, appeared to narrow to about 15 feet in width and was about 20 feet above the lower pit.


  • The mine operator had purchased this mine site approximately seven years ago. Within the past few months they had installed equipment consisting of an impact crusher, conveyors, grizzly and feed hopper. At the same time, Mitchell had been hired to run the equipment and direct operations at the pit.


  • Prior to the hiring of Mitchell, approximately 7 months ago, production responsibilities had been up to the drivers transporting the cinders. They were told what color and quantity of cinder was required. Drivers would then load their own trucks. Material had been scraped from the highwalls with the loader bucket wherever it was easily accessible. Typical scrape marks and an undercut section of the highwall were visible at the base of the south highwall. In addition, there were signs of undercutting as evidenced by tooth marks on the highwall made by a front-end loader.


  • The top of the highwall face was often void of scrape marks, but was still relatively vertical, suggesting that material from the upper half of the walls sloughed off as the lower half was undercut. Statements indicated that a commonly used production technique involved vibration to induce wall failure. Apparently, this was accomplished by spinning the dozer in place while simultaneously slamming the blade on the ground. A picture taken prior to the accident showed track marks of this nature immediately in front of the highwall. This is consistent with the condition of the highwall in the vicinity of the accident as well as other locations where there are no scrape marks near the top. The section of highwall between the west edge of the fall and the "point" did not have scrape marks from the loader as it did in the northwest corner. It was difficult to determine if this entire area failed as one event, or whether a smaller portion, immediately adjacent to the "point", was the target of induced failure.


  • No natural discontinuities such as joints or faults were evident in the highwall faces. However, tension cracks forming detached slabs were observed on both the north and south highwalls.


  • Kona Cinder and Soil, Inc. had not notified MSHA of its operation. In addition, Kona Cinder did not have a training plan as required under 30 CFR § 46. There was no evidence that the victim had received any previous training before working for Kona Cinder and Soil, Inc.


    • CONCLUSION

    The root cause of the accident was the failure to establish mining methods to maintain wall, bank and slope stability.

    ENFORCEMENT ACTIONS

    ORDER No. 7997087 was issued on April 10, 2001, under the provisions of Section 103(k) of the Mine Act:

    A fatal accident occurred at this operation on April 2, 2001, when the highwall collapsed on the operator and the dozer. This order is issued to assure the safety of all persons at this operation until MSHA has determined it is safe to resume normal operations. The mine operator shall obtain approval from an authorized representative for all actions to recover or restore operations to the affected area.

    The order was terminated on May 10, 2001, when it was determined by MSHA that the conditions, which contributed to the accident, no longer existed and normal mining operations could resume.

    CITATION No. 7997246 was issued on May 2, 2001 under the provisions of Section 104(a) of the Mine Act for a violation of 30 CFR § 56.3130.

    A fatal accident occurred at this operation on April 2, 2001, when the mine foreman was buried under a highwall that collapsed. The victim was operating a bulldozer at the toe of the highwall when it failed. Mining methods that would maintain wall, bank and slope stability had not been used.

    Related Fatal Alert Bulletin:
    Fatal Alert Bulletin Icon FAB00M09



    Photographs of Mine Site

    Appendix C (Map of Mine Site)

    APPENDIX A


    Kona Cinder and Soil, Inc.
    Charles Harlan .......... president
    State of Hawaii
    Department of Industrial Relations
    Division of Occupational Safety and Health
    Charles Clark .......... state inspector
    Mine Safety and Health Administration
    Larry Larson .......... supervisory mine safety and health inspector
    Harvey Brooks .......... mine safety and health inspector
    Paul Tyrna .......... geological engineer
    John Kathman .......... mine safety and health specialist
    APPENDIX B


    Persons interviewed during the investigation:

    Kona Cinder and Soil, Inc.
    Charles Harlan .......... president
    Jerime Torres .......... truck driver
    Johnnie Kane .......... truck driver
    H.O.V.E Road Maintenance
    Rudolph Kaupu .......... truck driver
    Jean Redman .......... executive director