losive, and advised that ???In the US ??? [ingredients] could be found at places such as Home Depot, Sears and Wal-Mart.??? In the winter 2010 issue, Khan published a detailed guide for ???Destroying Buildings,??? with advice on the ???best gas to use??? and instructions on how to find ???the center of gravity ??? the points in the building that if destroyed would cause the fall of the building.??