Abstract: At 9:15 p.m. on August 10, 2018, during a Blast Furnace outage, Employees #1 through 6, Boilermakers, and several other coworkers, were removing the lower cone of a 38 foot, 1-1/4 inch diameter by 87 foot, 2-inch height Blast Furnace Flue Dust Catcher attached with a bolted flange. The Blast Furnace Flue Dust Catcher was reportedly clogging, as evidenced by hydro-jetting records for prior service, and before and during the blast furnace shut down. Three 10-ton air hoists were attached to the upper and lower cone flanges. As Employees #1 through 6 cut every other bolt around the flange, including the last bolt with a torch, three of the air hoists failed and then, the lower cone struck a scaffold in use by Employees #1 through 6 and also the second floor deck, which was located approximately eight feet below. The hot contents of the Blast Furnace, Flue Dust Catcher was released and engulfed Employees #1 through 6. The contents of the dust hazard was not reported; however, as a result of the incident, Employee #1 was hospitalized with serious inhalation burns to his lungs and face; Employee #2 was hospitalized with burns to his face and neck with dust inhalation exposure; Employee #3 was treated for contusions to the neck, head, and chest with dust inhalation exposure; Employee #4 was treated for contusions to the leg and knee with dust inhalation exposure, and Employees #5 and #6 were also treated for dust inhalation exposure.