On March 26, 2000, the largest concrete domed structure in the world was reduced to a pile of rubble in a dramatic implosion lasting less than 20 seconds. According to Mark Loizeaux, whose Maryland-based Controlled Demolition Inc. was hired to bring the 24-year-old Seattle Kingdome down, "We don't blow things up. We use explosives as an engine, but gravity is the catalyst that will bring it down." Destroying the Kingdome was the most complicated of the 7,000 demolitions Loizeaux's company had undertaken. Nearly three months of preparations were needed to implode the dome, at a total cost of $9 million. The Kingdome was considered to be one of the strongest structures in the world, containing over 25,000 tons of concrete, with each of its 40 vaulted ribs incorporating seven lengths of 2-inch reinforcing steel bar. Strands of orange detonating cord-basically dynamite in a string that explodes at the lightning pace of 24,000 feet per second -connected six pielike divisions of the Kingdome to a nearby control center. Throughout each section, Controlled Demolition workers drilled nearly 1,000 holes and packed them with high-velocity gelatin explosives the size of hot dogs. Large charges were placed about one-third of the way up each dome rib; smaller charges were put farther up the ribs. When the detonation button was pushed, blasting caps set off a chain reaction of explosions in each section, reducing the stadium to rubble. While the actual implosion was a technical tour-de-force, risk management was a critical part of the project's success. To minimize damage to surrounding buildings, the explosive charges were wrapped in a layer of chain-link fencing covered with thick sheets of geotextile polypropylene fabric to contain flying concrete. Nearby buildings were protected in various manners depending on the structure and proximity to the Dome. Measures included sealing air-handling units, taping seams on doors and windows, covering floors and windows with plywood, and draping reinforced polyethylene sheeting around the outside How did Controlled Demolition Inc. respond to the risk