Fatality Assessment and Control Evaluation (FACE) Program
Hispanic Laborer Electrocuted After Boom Truck Contacts Overhead Power Line - North Carolina
On November 3, 2004, a 44 year-old Hispanic laborer (the victim) was fatally injured after being electrocuted through indirect contact with a 7,200 volt overhead power line. A boom truck with an auger attached (Photo 1) was turning a utility pole anchor in an anchor-setting process in preparation for a utility pole replacement. During the process, the anchor began to wobble and the extended boom contacted the overhead power line. Apparently unaware that the boom was in contact with the overhead power line, the victim grabbed the energized anchor with both hands in an attempt to stabilize it and remained in contact with the energized anchor until the boom was moved away from the power line. Electrical current moved through the victim’s body from his hands to ground through his feet. The boom truck operator immediately called 911 on his cell phone and emergency medical services (EMS) arrived in about 4 minutes. CPR was immediately initiated and the victim was transported to the hospital where he was pronounced dead.
NIOSH investigators concluded that, to help prevent similar occurrences, employers should:
On November 3, 2004, a 44 year-old laborer (the victim) was fatally injured after being electrocuted through indirect contact with an overhead power line. On November 8, 2004, the North Carolina Department of Labor Occupational Safety and Health Division notified the National Institute for Occupational Safety and Health (NIOSH), Division of Safety Research (DSR), of the incident. On November 15, 2004, a DSR Associate Service Fellow met with the Compliance Safety and Health Officer (CSHO), North Carolina Occupational Safety and Health Division (NCOSH), investigating the incident. The NIOSH investigator reviewed the case with the town director of public works and the crew supervisor. A copy of the police report and photos were reviewed. The incident site was examined and photographs were taken. On February 2nd and 3rd, 2005, follow-up telephone conversations were held between the DSR Chief of the Fatality Investigations Team and the NCOSH CSHO.
The victim was a prisoner at a State correctional facility who was contracted to work full-time during the day with a municipal electrical service division. The municipality had a contract with the local State correctional facility to provide 8 prisoner-workers, and had assigned the victim to the electrical service division’s construction crew as a laborer. He was picked up each morning, along with 7 other prisoners at the prison by municipal (town) workers, and was returned to the prison each evening. The town also employs a total of 70 regular workers in the police, rescue, administration, public works, solid waste and recycling services. During work hours, the prisoner was not confined and was under the direction of a Correctional Agent (CA). In this case the CA was the crew supervisor who had taken the training necessary through the State correctional facility to become a CA.
The victim worked as a laborer on a three-person crew. He had lived in the NC area for over 4 years, but was a native of Mexico. He spoke and understood English fluently. He had been working on this electrical service division crew for about four months.
The victim had no formal or documented training in the electric utility construction industry. All training was provided on-the-job by the municipality. He was not able to attend the regularly scheduled safety training meetings because he had to return to the prison and thus would often miss the late afternoon training sessions; however, he was able to participate in the tailgate meetings held at the work site(s) each morning. It was reported that overhead power line safety was discussed on the morning of the incident. The victim’s routine responsibilities included monitoring and controlling the auger/anchor joint and the sway during drilling.
The equipment used in the case was a powered boom truck designed and used to hoist and set utility poles. It had recently been inspected and passed its semi-annual dielectric (a non-conductor of electrical current) test. However, the design of the boom does not accommodate for the complete isolation of the truck, only a portion of the boom. Therefore, electric current passed from the point of contact down through the auger and victim to the ground. This was the town’s first workplace fatality.
The municipal electrical service provides power to approximately 5,000 homes and businesses in the area. As part of a system-wide upgrade in services, a replacement utility pole was to be set to support an existing power line. Then a guy pole was to be set approximately 30 feet from the pole and an anchor was to be set approximately 18 feet from the guy pole.
The town picks up 8 prisoner-workers from the State correctional facility each morning, and two are assigned to the municipal electrical service division. The electrical division also employs a total of 12 regular workers. The victim was picked up at the prison at approximately 6:15 a.m., taken to the office for assignments, and he then accompanied the crew to pick up materials. At 8:00 a.m., the victim, crew supervisor, the boom truck operator, and a second ground crew member arrived at the work site. The crew supervisor reportedly conducted a tailgate safety meeting to discuss hazards, which included overhead power line hazards, but no documentation was kept of any tailgate safety meetings. After the tailgate safety meeting, the guy pole was set and the anchor position was located.
To install the anchor, the distal end of the boom truck auger is fitted with a coupling allowing the attachment of the eye ring on the end of the six foot anchor. The auger motor rotates and the anchor is slowly screwed (set) into the ground.
As the anchor was being set, it broke. At 8:30 a.m., the crew was sent to the material yard to get a second anchor and the crew supervisor left the scene to check on other work. At 9:20 a.m., the crew was back at the site with an eight foot long, ten inch wide auger-end anchor. At about 9:30a.m., the crew located the anchor position and noted that there was a clearance issue due to the longer anchor and the proximity of the boom to the overhead power line. The crew began to dig a nineteen inch deep, twelve inch wide pilot hole to accommodate the longer anchor and maintain clearance from the power line.
At about 9:50 a.m., the ground crew connected the anchor to the end of the auger and placed the anchor into the hole. A few minutes later the boom truck operator began turning the boom auger and setting the anchor. Because of the angle of the required hole (see Photo 1) the rotating auger/anchor pivot point began to wobble, causing the boom to sway. The victim went over to the anchor and grasped it with both hands to likely try to stabilize it. The boom truck operator saw the victim approach the anchor and called to the victim to stop. The victim, despite the boom truck operator’s attempt to warn him, reached for the anchor at the same time the boom operator heard a ‘zapping’ noise and saw the victim holding the anchor. Electrical current moved through the victim’s body from his hands, through his torso, and to the ground through his feet. Realizing that the victim was in contact with the energized anchor, the operator moved the boom away from the power line and the victim fell to the ground.
The boom truck operator then called 911 on his cell phone. Another ground crew member called the crew supervisor on the two way radio. EMS arrived in about 4 minutes, began CPR and transported the victim to the hospital where he was pronounced dead at 10:30 a.m.
Cause of Death
According to the medical examiner’s report, the cause of death was electrocution.
Recommendation #1: Employers should conduct a jobsite survey to identify potential hazards and develop and implement appropriate control measures for these hazards.
Discussion: Before beginning work at any site, a competent persona should evaluate the site to identify any potential hazards and ensure appropriate control measures are implemented. The jobsite had identifiable hazards (i.e., a 7200-volt overhead power line) in close proximity to where the work was being performed.
In this incident, appropriate control measures may have included designating a safe area at the work site where the employees should remain until the hazard was mitigated and disconnecting the power to the lines. Alternatively, the procedure could have been modified, such as digging a larger and deeper pilot hole to accommodate the longer anchor and ensure proper clearance with the power line. Regardless, equipment should be located in a manner which does not create a hazard at the jobsite. Additionally, an area should be designated and marked (perhaps with barricades) at the work site. to provide the safest location for employees to remain while the auger was rotating and the boom of the truck was in close proximity to the power line.