For safety, the building is completely stripped of inner walls, windows and balcony railings. This preparation can take weeks or months. Electricity, gas and heat supplies are discontinued. Fencing is erected around the site to prevent unauthorised persons from entering. This is sometimes guarded at night. Explosives are strategically placed within the shell of the building, and these are detonated in a rhythmic fashion so that the structure will collapse in a particular way. Most of the time, the explosives are detonated to make the tower block collapse in on itself, reducing the risk of flying debris.
Such detonations are usually carried out on Sundays or bank holidays when there will be less inconvenience to local infrastructure. In early years, people have been killed in demolitions for example at Queen Elizabeth Square where an old lady was hit by debris. Some people have also committed suicide by remaining in the block during detonation.