Literally hundreds of building implosions have been caught on film in the past 25 years. An implosion is a controlled detonation that places charges at key points on a building. When these structural points are blown up, the building falls down under the weight of its own gravity. Casinos and stadiums are the two most common types of buildings that are imploded, but office buildings, bridges and other types of structures are also imploded.HowStuffWorks: "How Building Implosions Work"