On March 26, 2000, the firm used 4,450 pounds of dynamite placed in 5,905 carefully sited holes and 21 miles of detonation cord inserted over a period of four months to take down the 25,000-ton concrete roof of the Kingdome in Seattle, Washington in 16.8 seconds, one day before the 24th birthday of the stadium that had been the home of the Seattle Mariners of Major League Baseball and the Seattle Seahawks of the National Football League.