EXPLOSIONS IONS WE CREATE ON PURPOSE 三 3 C 3..2.1 How do you go about knocking down 50 floors of building? Preparation The team behind the demolition will usually create a 3D computer model of the building to work out where the dynamite needs to be put so the building can fall safely. The easiest way to demolish a building is to let it fall to one side， but if that's not possible， they'll need to place explosives so it collapses in on itself.