Operators in a powdered metals production facility heard a hissing noise near one of the plant furnaces and determined that it was a gas leak in the trench below the furnaces. The trench carried hydrogen, nitrogen, and cooling water runoff pipes as well as a vent pipe for the furnaces.

Maintenance personnel presumed that the leak was nonflammable nitrogen because there had recently been a nitrogen piping leak elsewhere in the plant. Using the plant's overhead crane, they removed some of the heavy trench covers. They determined that the leak was in an area that the crane could not reach, so they brought in a forklift with a chain to remove the trench covers in that area.

Eyewitnesses stated that as the first trench cover was wrenched from its position by the forklift view more

The interior of a small high-temperature furnace, approximately 24 inches high by 18 inches wide, became contaminated with an unknown material later identified as magnesium. The furnace was disassembled to clean the unknown material from the interior surfaces, and while attempting to clean the bottom of the furnace, the technician tapped the upper lip of the furnace with a spatula and the magnesium flashed. The technician was stepping back from the furnace when the magnesium flashed. He received minor eye irritation and his eyebrows were singed.

Later that week the same technician was attempting to clean the interior surfaces of the top of the furnace and sprayed, as directed, the interior of the top with a water-based cleaning liquid which consisted of 91% water. He stepped view more