UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION

South Central District
Metal and Nonmetal Mine Safety and Health

Accident Investigation Report
Underground Nonmetal Mine

Fatal Fall of Roof Accident

Southwest Lime Quarry I.D. No. 23-00202
Masters-Jackson Quarry
Neosho, Newton County, Missouri

May 10, 1996

By
Robert R. Lemasters
Mine Safety and Health Inspector
and
Felix A. Quintana
Assistant District Manager

Originating Office
Mine Safety &and Health Administration
1100 Commerce St. Rm. 4C50
Dallas, Tx. 75242-0499
Doyle D. Fink
District Manager

GENERAL INFORMATION

James E. Barr, laborer, age 45, and Brian Scott Wheeler, driller, age 27, were fatally injured at about 1:00 p.m. on May 10, 1996 when a massive roof fall occurred and crushed the welding truck with the two men inside. Bar had 4 months mining experience, all as a surface laborer at this operation. This was his first day underground. Wheeler had 9 months mining experience, 3 months working on the surface and 6 months as a driller underground, all at this operation.

The MSHA Rolla, Missouri field office was notified by a telephone call from Alice Leech, scale house clerk for the Southwest Lime Quarry, at 1:30 p.m. on the day of the accident. An investigation was started the same day.

The Southwest Lime Quarry, an underground limestone mine, was leased and operated by Masters-Jackson Quarry since 1993 and was located in Neosho, Newton County, Missouri. Operating officials were William Eckhoff, president, and George L. Doubledee, superintendent. The mine operated one 9-hour shift, 5 days a week, A total of twelve persons was employed; five underground and seven on the surface.

The single level adit mine was a random room-and-pillar mine, with pillars about 25 feet in diameter and average room spans of about 55 feet. By 1991 the mine had reached its maximum areal extent, within 25 vertical feet of the surface horizon and was not feasible to develop further laterally. After ramping down to a new lower floor level of an area west of Tunnel #2, benches were drilled by Master-Jackson Quarry Co. on the upper level. Econex, Inc. was contracted to do the blasting. Master-Jackson Quarry loaded broken limestone with a 7 yard WA600 Komatsu Loader into Eculid 25 ton haulage trucks and transported it to the primary crusher on the surface where they screened and sized the product for aggregate.

The last regular inspection of this operation was completed on February 1, 1996. The victims had not received training in accordance with 30 CFR Part 48.

PHYSICAL FACTORS

The accident occurred in an area north of Tunnel #2 about 150 feet north of pillar 36. The room on top of the bench was approximately 17 feet high and 40 feet wide by 50 feet long, however it reached heights of about 27 feet above the lower level. The roof horizon at the accident site was approximately 25 feet vertically from the surface. The fall was approximately 30 feet by 40 feet by 3 feet thick and weighed an estimated 250 tons. Though some large pieces of rock were pulled off the «-ton pickup truck, most measured less than 2 feet across, a significant portion ranging from less than 6 inches to gravel size and finer.

The floor had been mined in this manner for several months in three sections of the property, including the area of the accident. At about 12:00 p.m., on the day of the accident, two bench blasts were shot in the area north of Tunnel # 2. An Ingersoll-Rand single boom jumbo drilled 3 1/4-inch diameter holes 11-1/2 feet deep on 10 foot spacing. Using a V-echelon timing pattern, a sequential timer activated the two circuits with an interval of 15 milliseconds. Forty-six holes were shot between pillars 31, 34, 37, and 38; ninety-four holes were shot immediately southwest of the roof fall area.

The roof rock in the general area appeared weathered, discolored and mud-stained. The rock in the fall area was wet but not dripping water. It was concluded by MSHA Technical Support engineers that the highly broken nature of the fall material suggested erosion by water over a period of time.

The company did not install any additional roof support, such as roof bolts during the bench mining operations and no means were provided for sounding the 17- or 27-foot high roof. The only means provided for scaling the roof and pillars was to use the bucket of the WA600 Komatsu front-end loader, which has a maximum reach of twenty two feet, ten inches. Normal practice at this operation was to visually check blast for misfires. However, the examination of ground conditions was not being part of the post blast checks.

The 1987 Ford F-150 4x4 welding truck demolished in the accident was equipped with a portable generator to generate power to operate the portable lights at the blast site.

DESCRIPTION OF ACCIDENT

On the day of the accident James E. Barr and Brian Scott Wheeler (victims) reported for work at 7:00 a.m., their normal starting time. Wheeler operated the water truck underground until about 8:00 a.m. when he showed David Hersey and Anthony Smith, contract blasters where the holes had been drilled in the floor. He then set up the portable light system, and began assisting in loading the rounds to be shot. Due to excessive rainfall the surface operation was shut down and four employees were sent home at about 8:30 a.m. Leech, scalehouse operator, Ellis, yard loader operator, Wheeler, driller and Barr, laborer, remained. At about 9:30 a.m. Barr was assigned by Doubledee to assist Wheeler, Hersey and Smith in loading the rounds north of tunnel # 2. At 11:50 a.m. they drove to a designated area in the mine where they fired the rounds.

After waiting approximately 45 minutes for the smoke to clear they returned to the blast site. Barr, Wheeler, and Hersey parked the welding truck on the upper bench overlooking the blast site so the headlights could illuminate the shot area. Smith who followed in the explosives truck was instructed by Hersey not to bring the truck any closer, because flyrock on the floor might damage the tires.

The four men got out of the vehicles and examined the results of the blast for about three minutes and determined that the explosives had broken the material as planned. Hersey and Smith got back in the explosives truck and began backing out. Barr and Wheeler got in the welding truck. After backing about five feet, the roof fall occurred and crushed the truck to a height of 2 to 2.5 feet.

The windshield of the explosives truck, which was about ten feet away from the fall, was immediately covered with mud. Although they had obscured vision, the two contract blasters realized what happened and immediately drove out of the mine to report the accident.

Hersey and Scott Ellis, yard loader operator, returned to the fall area and attempted to verbally contact the victims but received no response. The rescue squad from the Newton County Fire Department was contacted and arrived at 1:11 p.m.

The Komatsu, WA 600 front-end loader was used to remove some of the large rocks from the top of the welding truck and smaller rocks were removed with a John Deere, 310 backhoe. The Rescue squad determined that both men were dead and the welding truck was pulled near the Tunnel #2 entrance to remove the victims from the truck. The Newton County coroner pronounced the two men dead at the scene.

CONCLUSION

The direct cause of the accident was the failure to take down or adequately support hazardous roof before work or travel was permitted in the mining area. The failure to designate experienced persons to conduct proper examinations and to test ground conditions prior to work commencing was an indirect cause. Other indirect causes were the failure to adequately train miners in the hazards associated with underground mining and the proximity of this working area to the surface.

VIOLATIONS

Citation No.4448535

Issued on July 1, 1996, to the mine operator, under the provisions of Section 104 (d) (1) for violation of 30 CFR 57.3200.

The mine operator had not taken down or supported hazardous ground conditions in any work area of the recently reopened underground mine. A double fatality occurred on may 10, 1996 when a roof fall, approximately 30-foot by 40-foot by 3-foot, weighing approximately 250 tons, fell on two miners after blasting a 10-foot bench north of tunnel #2 The victims had driven in a welding truck to the area which had not been scaled or provide with roof support. This is an unwarrantable failure.

Order No. 4448536

Issued on July 1, 1996 to the mine operator, under the provisions of Section 104 (d) (1) for violation of 30 CFR 57.3401

The mine operator had not assigned appropriate supervisors, or any other persons experienced in mining, to examine and test ground conditions in work areas of the underground mine, prior to work commencing, after blasting, and as ground conditions warranted. On May 10, 1996 a massive fall of ground occurred at an area north of tunnel # 2, after a 10-foot underground bench was blasted, fatally injuring a drill operator and a laborer. The operator of the recently reopened underground mine had not obtained appropriate equipment for examining and testing the 17-foot high roof, including scaling bars, high lifts, or other means to examine and scale the roof. This is an unwarrantable failure.

Citation NO. 4448537

Issued on July 1, 1996 to the mine operator, under the provisions of Section 104 (g) for a violation of 30 CFR 48.5

A massive fall of ground occurred at an area North of Tunnel # 2 fatally injuring two miners inexperienced in underground mining on May 10, 1996. Brain Scott Wheeler, driller began work for the company in August 1995 and received two days of New Miner Training on December 5-6, 1995. James Barr, laborer began work for this company in January 1996 and received two days training on April 30 & May 1, 1996, however the day of the accident was his first day underground, Neither miner had experience working in underground mines.

Citation No.4448661

Issued on July 30, 1996 to the blasting contractor, under the provisions of Section 104 (d)(1) for violation of 30 CFR 57.3401.

The blasting contractor did not examine and test the roof conditions after blasting and prior to reentering the blast area on 5/10/96. A massive fall of ground occurred at an area north of tunnel 2, after a 10-foot underground bench was blasted, fatally injuring a drill operator and a laborer working for the mine operator. The blaster and the helper returned to the blast area with the two victims after the blast, but neither the mine operator or contract employees examined or tested the roof prior to entering the area. This is an unwarrantable failure.

[FAB96M19]