Hydrogen sulfide fumes from a 12-foot-deep sewer line killed four workers on Nov. 1 at the Lakehead Blacktop Demolition Landfill in Superior, Wis. The level of deadly gas at the bottom of the 3-foot-diameter manhole was so high that it would have immediately knocked them unconscious, according to experts at the scene.Paul E. Cossalter, 41, died along with brothers Joseph P. Kimmes III, 44, and Scott A. Kimmes, 40, and Harold Tim Olson, 47. After the first man entered the manhole and collapsed, the others followed as each one saw the previous rescuer succumb. Two other workers at the privately
