A short circuit issue that energized a residential dock frame is what caused the electrocution death of an Illinois man June 21 at Lake of the Ozarks.
According to a news release issued by Osage Beach Fire Chief Jeff Dorhauer, the Osage Beach Fire Protection District was called to a possible electrocution at the residence off Route KK June 21. The district’s investigation discovered the occupants of the home had reported problems with the dock’s electric to the homeowner earlier that afternoon. The occupants said the breaker would trip after being reset, holding for a period of 10 to 15 seconds and would then trip, Dorhauer said.
On the evening of June 21, 21-year-olld Marcus Colburn, East Moline, Illinois, and a female minor, Taylor Curley, also of East Moline, were swimming in the lake off the residential dock when the home’s occupants again tried to reset the breaker, according to the Osage Beach Fire Protection District’s investigation. At this time, Colburn and Curley felt electrical current in the water and Colburn took hold of the ladder to exit the lake causing his apparent electrocution.
According to the Missouri State Highway Patrol’s incident report, Colburn was taken to Lake Regional Hospital, and Dr. Patrick Greenwood pronounced him dead at 10:14 p.m. June 21. Curley suffered minor injuries from the incident and was taken to Lake Regional Hospital for treatment.
Dorhauer said on June 22, investigators located a junction box under a deck on the house. This junction box was fed from the breaker panel in the house and then fed the disconnect at the shoreline. When the conductors were disconnected in this junction box, the breaker would no longer trip. When the conductors were removed from the junction box, there was clear evidence that they were hot and the ground conductors had been arcing, the investigation revealed.
The investigation found the circuit breaker and system operated as designed, and the short circuit was breaking the circuit from the arcing at the junction box. Arcing between hot and ground was feeding power into the equipment grounding conductor that is tied into the grounding rod at the shoreline. This ground rod is tied to the dock, which fed power into the dock frame and caused the frame to become energized, Dorhauer said in a news release. Each attempt to reset the breaker and turn the power on would have resulted in an energizing of the dock and the water until the breaker tripped again, the investigation report stated.
Dorhauer said in the investigation the junction box was visually inspected during two earlier inspections on dates of May 30, 2014, and Oct. 30, 2014. This inspection was visual of the box only to insure it was weather tight and correct type for the usage, however the box was not opened, the news release said. Dorhauer said the inspection of the wiring inside this junction box would not have indicated a problem and the inspection checklist calls for the following in relation to this junction box: “Junction box on outside of building serving the dock shall be weatherproof or approved method per AHJ.”
The Highway Patrol’s Water Division secured and removed the junction box and wiring in question from the property.
The following individuals assisted or witnessed the investigation: Dorhauer, Osage Beach Fire Marshal Ed Nicholson, Jeff Green of Ameren Missouri, David Hagan of Ameren Missouri, Highway Patrol Capt. Matt Walz and electrician Mark Beaubout.