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UNITED STATES DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION

Southeastern District
Metal and Nonmetal Mine Safety and Health

Accident Investigation Report
Surface Nonmetal Mine
(Limestone)

Fatal Fall of Highwall Accident

D&H Drilling, LLC
I.D. No. 1VW

at
Hanson Aggregates East, Incorporated
Tiftonia Quarry
Chattanooga, Hamilton County, Tennessee
I.D. No. 40-00060

February 27, 1999

by

William L. Wilkie
Supervisory Mine Inspector

Joel B. Richardson
Mine Safety and Health Inspector

Lawrence G. Wilson
Civil Engineer

Robert A. Barrish Civil Engineer

Originating Office
Mine Safety and Health Administration
135 Gemini Circle, Suite 212
Birmingham, Alabama

Martin Rosta
District Manager

GENERAL INFORMATION

Onita L. Davis, contract driller, age 45, was fatally injured at about 9:00 a.m. on February 27, 1999, when she was struck by a rock that fell from a highwall. Davis had a total of 6 years experience as a driller with the contracting company. She had received training in accordance with 30 CFR, Part 48.

MSHA was notified of the accident at about 11:00 a.m. on the day of the accident by a telephone call from the area safety manager for the mining company. An investigation was started the same day.

The Tiftonia Quarry, a crushed stone operation, owned and operated by Hanson Aggregates East, Incorporated, was located adjacent to Highway 24 in Chattanooga, Hamilton County, Tennessee. The principal operating official was Randy Raines, plant manager. The mine was normally operated one, 8-hour shift a day, five days a week. Total employment was 18 persons.

Limestone was quarried from a single bench in the pit. It was drilled, blasted, loaded by front-end loaders onto haul trucks, then transported to the plant where it was crushed, screened and sized. The final product was sold for use as construction aggregate.

The victim was co-owner of D&H Drilling, LLC, an independent contractor located in Whitwell, Marion County, Tennessee. The principal operating officials were Onita Davis, president, and Mona Lisa Hudson, vice president. D&H Drilling was at the mine site to drill blast holes.

The last regular inspection of this operation was completed on November 19, 1998. Another inspection was conducted at the conclusion of this investigation.

PHYSICAL FACTORS INVOLVED

The accident occurred at the northern face of the pit on the quarry floor. The face was approximately 380 feet wide at the base. The highwall, where the accident occurred, was about 232-feet high. The walls of the pit were predominately limestone interspersed with shale and mud layers. There were loose and fractured rocks along the northern rim and face of the quarry directly above the accident site. Loose rock fell throughout the investigation.

The drill used by the victim was a Tamrock T40 KS drill owned by D&H Drilling. At the time of the accident it was positioned parallel to, and 20 feet away from, the highwall on the quarry floor. The contractors were to drill several holes to a depth of 12 to 15 feet on 14-foot centers preparatory to blasting the quarry floor so it could be leveled.

A drill owned by Jackson Enterprises was drilling on the top bench at the time of the accident. It was positioned about 120 feet west of the site where the rock fell. Holes had been marked off about 8 feet from the rim of the pit along the north face. On the day of the accident, one hole had been drilled to a depth of about 175 feet. A 988 Caterpillar front-end loader and two, 35-ton haul trucks were also being used to strip overburden on top of the bench. The trucks traveled parallel to the pit wall and passed within 30 feet of the rim, directly above the drill on the quarry floor. It was estimated that six loads of overburden had been hauled out prior to the accident.

A rock found near the victim, believed to have been the one that struck her, measured about 4 by 4 by 3 inches and weighed 2 pounds, 13 ounces.

Weather, on the day of the accident, was cloudy with periods of rain that varied from light drizzle to heavy downfalls.

DESCRIPTION OF ACCIDENT

On the day of the accident, Onita Davis (victim) and David Davis, driller and the victim's husband, reported for work at the quarry at 7:00 a.m.. After changing a leaking hydraulic hose, they positioned the drill near the quarry face and drilled two holes.

At about 9:00 a.m., Onita Davis was measuring the depth of the second hole while David Davis moved the drill to begin the next hole. When David Davis got out of the cab of the drill he saw Onita Davis lying on the ground. Her hard hat had been broken and she had sustained injuries to the head and neck from a rock that had fallen from the highwall. He moved her to a safer location and went to the mine office to summon help. Grady Brooks, pit foreman, called the local 911 emergency assistance number. Paramedics arrived a short time later but efforts to revive Onita Davis were unsuccessful. The medical examiner pronounced her dead at the scene.

CONCLUSION

The cause of the accident was failure to scale loose material from the highwall. Vibrations from equipment operating on top of the quarry may have contributed to loosening the rock. The height of the wall was not conducive to effective scaling.

VIOLATIONS

Hanson Aggregates East, Incorporated

Citation number 7760982 was issued on March 25, 1999, under the provisions of Section 104(d)(1) for violation of 30 CFR 56.3200:
A contract driller was fatally injured at this operation on February 27, 1999, when a rock fell from the highwall striking her on the head. The contractor was drilling shallow holes in order to level the floor and the victim was measuring a hole that had just been drilled about 20 feet from the highwall when the rock fell. Loose ground had not been taken down or supported before work was permitted in the area. Failure to scale loose ground is a serious lack of reasonable care which constitutes more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.
Citation No. 7760983 was issued on March 25, 1999, under the provisions of Section 104(a) for violation of 30 CFR 56.3130:
A contract driller was fatally injured at this operation on February 27, 1999, when a rock fell from the highwall striking her on the head. The contractor was drilling shallow holes in order to level the floor and the victim was measuring a hole that had just been drilled about 20 feet from the highwall when the rock fell. The mining method did not maintain wall, bank and slope stability in that benching was not used to lower the height of the quarry wall so that scaling and corrective work could be effectively performed.
Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB99M09

APPENDIX 1
List of Persons Present During the Investigation.


Hanson Aggregates East, Incorporated

Randy L. Raines ...................... plant manager
Grady Brooks ...................... pit foreman
Thomas C. Hutto ...................... area manager safety and environment
C. Ken Stockton ...................... director of safety and environment
David C. White ...................... corporate safety director
Michael T. Heenan ...................... attorney


D&H Drilling, LLC

Mona Lisa Hudson ...................... vice president
David A. Davis ...................... drill operator

Jackson Enterprises

Michael W. Scruggs ...................... drill operator
Johnny Neal ...................... drill operator

Mine Safety and Health Administration

William L. Wilkie ...................... supervisory mine inspector
Joel B. Richardson ...................... mine safety and health inspector
Lawrence G. Wilson ...................... civil engineer
Robert A. Barrish ...................... civil engineer


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