How are skyscrapers, located in the middle of cities, demolished?

Explosives and sequential deconstruction.

Dynamite followed by a lot of cleanup!!! It’s actually an amazing thing to watch. With the explosives placed in the appropriate location, the building just kind of folds into itself with anything around it still intact & covered in dust. Here is a good example. The World Trade Center Tower was also an example of how it could happen.

This one is in Germany

Watching buildings come down by purposefully imploding them is amazing. How they figure out how to do it, just the right amount of explosives. They do clear people away a certain amount of distance in case something goes wrong. I would guess that sometimes means an entire building or two might have to be evacuated for the event.

They are imploded so the building comes straight down within itself, and within a very small area.

It isn’t always possible to blow them up in densely built up areas and some high rise buildings have to be physically dismantled floor by floor using long reach mechanical excavators or even by lowering the entire building floor by floor on hydraulic jacks.

None of these techniques is very practicable with the tallest buildings now being built eg the 2,700 foot Burj Khalifa, and I don’t think anyone really knows how they can be safely brought down.

The Singer building was the tallest built in 1908 and the tallest destroyed in 1968.

The blog link below has a newspaper clipping showing it being dismantled. It looks just like a building being constructed, with a crane on top and exposed steel skeleton.

Scroll down to see “End of a Skyscraper” – A celebration of the Singer Building

If there are buildings adjacent you simply cannot use explosives.
In NYC buildings we see buildings dismantled floor by floor.
A novel approach was used in Tokyo on this building by enclosing the top with what amounts to a demolition factory.

A novel approach was used in Tokyo on this building by enclosing the top with what amounts to a demolition factory.

They have a similar construction technique in Japan, with a “factory” rising up as the people inside assemble the building.