The old 15-floor P&O Building in downtown London is being torn down to be by a new tower But unlike your usual building demolition, the process here is backwards: they're dismantling it from the bottoms up!
The lower levels of the building are being taken apart to reveal a concrete core running down its centre.
This is possible because each floor is hung from a huge beam at the top of the tower and supported by the central core. The 15-storey building, erected in 1965, is one of four in the capital to be constructed that way.
Project director Matthew White said: "When you demolish the building, you have to take the weight off the structure first, from the bottom up. "Eventually the beam will be deconstructed at roof level, leaving the core, which will be demolished from the top."