Abstract: At approximately 8:30 a.m. on September 1, 2015, an employer was upgrading natural gas lines as a subcontractor for Peoples Gas. A large vacuum truck, Vacmasters System 4000, Manufacturer Vacmasters of Denver, Model Number VND S4000, Serial Number 1003-798VNDS4, was being used to remove soil from various excavations. The vacuum unit was dumping soil in the yard of a vacant house of an alley. An employee, a laborer, was releasing soil from the spoil tank on the unit when the spoil tank became detached from the frame. The unit struck and pinned the employee beneath it. Excavating equipment was used to free the employee from beneath the unit. The employee was transported to a local hospital where the employee was pronounced dead. Coworker #1, crew leader, was operating the hydraulic functions of the Vacmasters System 4000, when the incident occurred and witnessed the equipment dislodge and the employee being trapped. Coworker #2, equipment operator, was summoned to operate heavy equipment to assist in freeing the employee.