Just as he'd done several times that summer, Pete brought along his 5-year-old daughter, Lindsey, to the general store he regularly serviced. Located in a rural community, the store had an equipment repair shop set up in a metal-sided shed out back. As her dad worked in the repair shop, Lindsey (dressed in a light summer dress and sandals) played just outside the sliding door on an aluminum ramp. A common childhood accident proved fatal when she tripped while walking across the ramp. As she grabbed the metal-covered sliding door to brace herself, she completed a circuit between the ramp and the door, electrocuting herself. After hearing the fall, Pete came outside to find his daughter lying motionless on the ramp. As he held her, her body produced a “tingling” sensation in his hands.
Tragically, Lindsey was pronounced dead at the hospital. A coroner later attributed her death to “irreversible anoxic brain damage as a consequence of electrocution.”
As in all accidents of this sort, the family wanted some answers. In this case, the family's attorney hired our firm to investigate the circumstances of their daughter's death. We performed a standard electro-forensic investigation that revealed a series of oversights, all of which were avoidable.
We began with a survey of the electrical system. Type NM cable (commonly known as Romex) fed the shed lighting and receptacle circuits from the store's circuit breaker panel. We found the wiring in the shed exposed and secured to the surface of the shed's wood framing. We also noted numerous wiring installation conditions that did not comply with the NEC. However, the circuit for the wall receptacle was properly grounded.
The repair shop, including the sliding door Lindsey grabbed when she fell, was covered in corrugated-metal siding. A battery charger, which plugged into a 120V wall receptacle, rested on the aluminum ramp just outside the door.
Police and other public investigative reports revealed the metal case of the battery charger had been in contact with the aluminum ramp. During our on-site recreation, tests showed the battery charger created a 38V to 44V potential between the ramp and sliding door. After subsequent laboratory examination of the battery charger, we discovered someone had installed a non-grounding type attachment plug on the 3-conductor power cord of the charger. The power cord's grounding (green) conductor was shorter than the energized (black) and neutral (white) conductors, and through microscopic examination of the conductor strands at the attachment plug terminals, we concluded several strands of the grounding conductor had contacted the energized screw terminal in the attachment plug.
In our report to the attorney, we explained the battery charger, and the metal ramp on which it sat, would have been energized when the grounding conductor strands contacted the energized terminal of the attachment plug. The metal-covered sliding door provided an adequate ground path for the electrocution to occur. Countless people had no doubt stood on the ramp while touching the door before, but Lindsey's small body and her open-toed sandals (which may have allowed her toes to touch the metal ramp) could explain why she was shocked.
We concluded that someone used an improper non-grounding type attachment plug to repair the charger power cord. This raised several questions. Had anyone ever routinely inspected the charger for proper ground continuity? Were workers instructed on proper maintenance techniques for the repair of power cords? What other procedures or training could, or should, they have practiced? We concluded Lindsey's death could have been avoided if someone had performed even one of these routine — and often required — tasks.
Several months after we submitted our report, the attorney informed us that the family had reached a confidential settlement with the store owner. The judge dismissed several other defendants, including the utility and the battery charger manufacturer.
The tragedy in this case was that this young girl's death was preventable — if only basic electrical standards had been followed. Numerous manufacturing standards, including those of the Underwriters Laboratories (UL) and the Canadian Standards Association (CSA), address the mechanical and electrical properties of power cords. Other codes and standards, such as those set forth by the NEC and OSHA, provide requirements for the application, use, and maintenance of power cords. Lindsey's death serves as an unfortunate reminder of how important it is for facility managers to follow these standards.
Foley is President of Technical Consultants Group, Ltd., Denver.