Abstract: At 2:30 p.m. on December 7, 2024, Employee #1, a test technician at Prolec-GE Waukesha, Inc., was working alone in the transformer manufacturing test area. Using a scissor lift, the employee elevated approximately 15 feet to the top of a newly built high-voltage electrical transformer to disconnect three-phase power by removing power leads as part of teardown after an electrical test. The electrical circuit had not been effectively deenergized or verified as deenergized visually or with testing equipment prior to the work. While loosening a nut securing one of the power leads, an arc flash occurred, causing electrical current to pass through the employee. The employee was thrown onto the surface of the transformer top, sustaining burn and electrical shock injuries resulting in electrocution. The electrical power involved was approximately 8,000 volts.