Swallowing skyscrapers
How to demolish a skyscraper one floor at a time.
First they replace the support pillars at ground level with computer-controlled metal columns. Then, a crew carefully demolishes the entire floor by hand, leaving the structure resting on the mechanical pillars, which then go down slowly until the next floor is at ground level. They replace the support pillars again with the mechanical ones, destroy that floor, and repeat the operation until they get rid of all the floors.
