Abstract: At approximately 12:40 p.m. on August 7, 1989, Employees #1 and #2 were operating a Tyler Model 2400 multi-spindle panel router, Serial Number 2984-87 when the high speed spindle assembly malfunctioned. The malfunction resulted in overheating and partial disintegration of the spindle assembly sending hot metal and burning wood dust into the Carter-Day dust collector system. The filter on the bag house exploded causing a back blast down the duct work. The ensuing back blast blew out around the multi-spindle panel router and burned two employees. Employee #1 was burned on his face and arms Employee #2 was burned on his face, arms, and back.