Abstract: On May 18, 2023, Employee # 1 and Employee #2 were in structure under construction. A diesel motor for a generator with an enclosed trailer caught on fire, the trailer also contained process equipment and materials for spray-applied polyurethane foam insulation. After unsuccessful attempts to extinguish with portable fire extinguishers, the fire spread outside the trailer involving the recently applied foam insulation on the two-story parking garage ceiling, spreading to a five-story wood frame structure above. Attempts by the fire department and a tower crane operator to rescue Employee #1 and Employee #2 were unsuccessful due to growing intensity of fire and smoke. The emergency action plan was inadequate, an audible alarm was not used to evacuate workers, and there was one vertical means of egress throughout the seven-story structure. Employee #1 and Employee #2 were killed in the fires and their remains were located and recovered the next day.