Abstract: At 8:30 a.m. on August 1, 2020, Employees #1, #2, and #3, employed by a electrical services company in the telecommunications field, were working on a multi-employer construction project at the intersection of two streets. They were potholing to locate underground utility lines, with the aim to then bore in a new fiber optic line under the intersection. After finding what they thought was over-pour from the concrete curb, they used a Ring-o-matic Vacuum Excavator to excavate over top of the concrete. They then used a jackhammer on the concrete. The jackhammer bit made contact with a 12,470-volt underground electrical distribution line, and an electric arc explosion occurred. Employees #1 and #2 were killed by electrocution. Employee #3, who was knocked down by the force of the explosion, was transported to the hospital, where he was observed, determined to have no injuries, and released.