UNITED STATES
DEPARTMENT OF LABOR

At approximately 6:07 p.m. on July 1, 1998, Employees #1 through #4, maintenance workers for Baxter Healthcare, were working atop a suspended grid ceiling in the injection molding department. Baxter Healthcare had hired Hill's Welding Service and Crane Rental to raise the existing roof support steel over a 68 ft by 24 ft section of the injection molding module to accommodate newer and taller injection molding equipment. Hot welding slag fell down from the top of an I-beam being installed onto an existing Armstrong ceiling with tile composed of mineral wool fiber. The hot slag ignited dust that had previously settled on top of the ceiling tile, resulting in a small smoldering fire. Employee #1 climbed a 10 ft tall cinderblock wall and began trying to snuff out the fire with his foot. Apparently either the smoldering fire burned through the tile allowing dust particles to become airborne in a combustible concentration, or his efforts disturbed the dust. The fire then flashed in all directions, consuming the suspended dust particles. Employee #1 fell through the suspended grid ceiling, which disturbed more dust particles and caused a more widespread flash dust fire. Employees #1 through #4 suffered first-, second-, and third-degree burns and were taken by coworkers to the local hospital. The dust was most likely composed of mineral wool fibers and finely ground polypropylene from pellets.