Skip to content
Metal and Nonmetal Mine Safety and Health


Surface Nonmetal Mine
(Sand and Gravel)

Fatal Machinery Accident
February 9, 2002

Onyx Portable 2
Onyx Construction, Inc.
Orogrande, Otero County, New Mexico
ID No. 32-00775

Accident Investigators

James M. Thomas
Supervisory Mine Safety and Health Inspector

Kevin L. Busby
Mine Safety and Health Inspector

Henry T. Tytor
Mine Safety and Health Inspector

Steve M. Powroznik
Mine Safety and Health Specialist

Dennis L. Ferlich
Supervisory Mechanical Engineer

Originating Office
Mine Safety and Health Administration
South Central District
1100 Commerce St., Room 462
Dallas, TX 75242-0499
Michael A. Davis, Acting District Manager


Arron Maldonado, Operator trainee, age 38, was fatally injured on February 9, 2002, when he was struck and crushed by the blade of the Caterpillar D-8L dozer he was operating.

The root cause of the accident was the failure to position the gear shift control in neutral and set the park brake before exiting the D-8L dozer cab.

Maldanado had nineteen weeks mining experience. He had received new task training that met the requirements of 30 CFR, Part 46.7 for the D-8L dozer.


Onyx Portable 2, a sand and gravel operation, owned and operated by Onyx Construction, Inc., was located near Orogrande, Otero County, New Mexico. The principal operating official was Jason N. Schoonover, Secretary/Treasurer. The plant operated two 10-hour shifts a day, six days per week. Total employment was 14 persons.

The portable plant had been in operation since June 29, 2001. Pit run material was pushed to the primary feed hopper with dozers where an excavator fed the material into the hopper. The material was conveyed to screens and separated. A radial stacker conveyor stockpiled the sand. The gravel was conveyed to the main processing plant where it was crushed, screened and stockpiled for sale as construction aggregate.

The last regular inspection at this operation was completed on August 9, 2001.


On the day of the accident, Arron Maldanado (victim) reported to work at 6:30 A.M. His regular starting time was 7:00 A.M. He reported to work early on this day to service machinery and equipment at the crushing plant.

Jason Schoonover, secretary/treasurer was operating the Caterpillar D-8L dozer, Gordon Schoonover, vice-president was operating the Cat D-9N dozer and Bent Means, dozer operator was operating the Cat D-9R dozer in the pit. Albert Schoonover, owner/operator was operating the Volvo 360 excavator feeding the material into the primary feed hopper. At about 10:00 A.M., Maldanado inquired of Jason Schoonover about operating the D-8L dozer.

Between 10:00 A.M. and 10:30 A.M., Maldanado observed Jason Schoonover operate the D-8L dozer and then operated it himself under observation of Schoonover. Maldanado had been previously instructed on the operational controls of the D-8L dozer, but had not operated the machine prior to the date of the accident.

At approximately 10:30 A.M., Jason Schoonover instructed Maldanado to operate the D-8L dozer, but only in low gear and half throttle until he became comfortable with the machine. Jason Schoonover left the area and Maldanado pushed material about half way up in the pit where the D-9N dozer operated by Gordon Schoonover picked up the material and pushed it up to the hopper. Bent Means operated the D-9R dozer also pushing about half way for the D-9N dozer to pick up. At approximately 12:00 P.M., lunch was delivered and all four persons operating equipment in the area parked their machines and ate lunch.

After lunch, Maldanado continued pushing material until approximately 1:00 P.M. when his dozer's low fuel light came on. Maldanado parked his dozer, dismounted and asked Means about the light. Then he trammed his dozer to the fuel tank located out of the pit and filled the dozer with fuel. Shortly after resuming operation, Means backed up past Maldanado to make another push. Before Means began pushing forward, he observed Maldanado in his operator cab with the dozer stopped and the blade on the ground. Maldanado remained stopped as Means pushed material past him.

Approximately 100 feet in front of Maldanado, Means stopped and looked back, before backing up. He saw Maldanado on the ground and his dozer moving in reverse. Means parked his machine, called on the radio for help and went to the scene of the accident and checked the victim for vital signs but could not find any. He went to the D-8L, which had stopped against the back slope of the pit. Gordon Schoonover also parked his machine and went to the scene. The D-8L was found idling in first gear reverse, the back up alarm sounding and the parking brake off. Means put the D-8L in neutral, set the brake and shut the machine off. State and county authorities arrived about fifteen minutes later and Maldanado was pronounced dead at the scene. Death was attributed to crushing injures.


MSHA was notified at 2:30 P.M. on the day of the accident by a telephone call from Gordon Schoonover, Vice President of Onyx Construction, Inc., to the Rocky Mountain District. An investigation began the same day. An order was issued pursuant to section 103(k) of the Mine Act to ensure the safety of miners. The accident investigation team made a physical inspection of the accident site, interviewed employees, reviewed training records and other information relative to the job. The miners were represented by the International Union of Operating Engineers, Local 953. The investigation was conducted with the assistance of mine management and the employees.


� The accident occurred at the pit, which was approximately 500 feet long and 66 feet wide. The pit had a highwall on the south side, approximately 60 feet in height. To the north was a waste area, which had a gradual slope up. To the west was the back slope with a grade of approximately 45 percent. The area of the accident had a grade of approximately 4 percent sloping down towards the back slope on the west end. The area also sloped slightly to the south. (Refer to Appendix D)

� The dozer involved in the accident was a 1983 Caterpillar model D-8L. The overall length of the dozer was approximately 21 feet. The dozer was equipped with a universal style blade approximately 14 feet 8 inches wide and 69 inches high. No other attachments were installed on the dozer. The transmission was a planetary-type power shift with three forward speeds and three reverse speeds in an inverted U-patterned console that was located to the left of the operator's seat. The service and parking/emergency brakes were hydraulically released, spring-applied, multiple wet-disc brakes. One service brake foot pedal located in front of the operator controlled simultaneous application of both service brakes. Both service brakes could also be simultaneously applied by pulling both steering control levers completely rearward. The parking/emergency brake was designed for manual application or automatic application in the event of loss of hydraulic pressure. The parking/emergency brake lever for manual application was located to the left of the operator's seat directly on the vertical panel of the transmission console. The brake lever operated by vertical motion. Operational testing of the dozer by MSHA technical support found no defects.

� The D-8L dozer traveled a distance of approximately 80 feet in reverse during the accident as measured from the original position of the blade to the point of the blade where the machine was found. The victim's body was found approximately 21 feet to the rear of the original position of the blade on the left side. The blade had an accumulation of material behind the right side of the blade at the point where the machine stopped after moving in reverse.

� According to statements collected, the transmission control was in first gear reverse with the parking brake off when the dozer was found immediately after the accident. The dozer engine was idling and the back up alarm was sounding. None of the three persons working in the area saw the accident.

� The investigation showed that Maldanado had been working with heavy equipment for about three years and had attended training on track hoes and dozers, although it had been several years since he had operated a track hoe or dozer. The victim had received training as a newly hired inexperienced miner and he had received initial task training on the operation of the D-8L dozer prior to operating it on the day of the accident.


The root cause of the accident was the failure to place the transmission control lever in neutral and manually engage the parking brake before exiting the cab of the Caterpillar D-8L dozer.


Citation/Order Issued to Onyx Construction, Inc.

Order No. 6214229 was issued on February 9, 2002 under provisions of Section 103(k) of the Mine Act:
The operator of a Caterpillar D8L track dozer was fatally injured at this operation on February 9, 2002. This order is issued to assure the safety of all persons at this operation. It prohibits all activity in the primary feed area including operation of the Caterpillar D-8L, Caterpillar D-9N, Caterpillar D-9R and the Volvo EC360 track excavator until MSHA has determined it is safe to resume normal mining operations in the area. The mine operator shall obtain prior approval from an authorized representative for all actions to recover and/or restore operations to the effected area.
This order was terminated on February 13, 2002, after it was determined that the mine could safely resume normal operations.

Citation No. 6216066 was issued on February 20, 2002, under the provisions of Section 104(a) of the Mine Act for violation of 30 CFR 56.14207:
A fatal accident occurred at this operation on February 9, 2002, when an employee was struck and crushed under the blade of the Caterpillar D-8L dozer, which he had been operating. The unattended dozer was left with the gear shift control in reverse first gear and the parking brake off.
This citation was terminated on March 25, 2002, when the operator provided written documentation of training of all employees on the proper procedures for securing all mobile equipment prior to dismounting.

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB02M07


Persons Participating in the Investigation

Onyx Construction, Inc.
Gordon L. Schoonover .......... vice-president
Jason N. Schoonover .......... secretary/treasurer
Albert G. Schoonover .......... owner/operator
Mine Safety and Health Administration
Kevin L. Busby .......... mine safety and health inspector
Henry T. Tytor .......... mine safety and health inspector
James M. Thomas .......... supervisory mine safety and health inspector
Steve M. Powroznik .......... mine safety and health specialist
Dennis L. Ferlich .......... supervisory mechanical engineer

Persons Interviewed

Onyx Construction, Inc.
Bent Means .......... equipment operator
Albert G. Schoonover .......... owner
Gordon L. Schoonover .......... vice-president
Jason N. Schoonover .......... secretary / treasurer