Residents watched on Sunday morning as one of Pretoria central’s numerous derelict buildings was demolished in billows of dust and reduced to piles of rubble within a few seconds.

The derelict, government-owned 15-storey HG de Witt building in Nana Sita Street was demolished as part of the national public works department’s disposal strategy for old and unsafe structures that have reached the end their lifespan.

Demolition contractor Jet Demolition managing director Joe Brinkmann said the risks of damage to adjacent buildings and people were minimal during the operation in densely populated Pretoria central on Sunday.

“The highest danger or risk in such an operation is people. The do always come first so we take measures to protect all the people. We had cleared a block to a block-and-a-half of the area surrounding this building to make sure everyone is away,” Brinkmann said.

“Regarding the buildings next to HG de Witt building, there is damage of impact. There is also damage of services in the street, that is, the pavements during the preparation phase. There is also risk to people working on this project who work at heights of over 40 metres in the air. So there was quite a number of risks which we had to control and mitigate.”

Brinkmann said the blasting at the “very tight site” surrounded by other buildings had gone very well. Engineers had to ensure that the building caved in to minimise damage to surrounding buildings and streets.

“Now we must clean up so that we open the streets. We have some spillage [of rubble] onto the pavements and we now have to clean it up. From next week we will come in and starting breaking it [rubble] up. We will take it away to be crushed down so that it can be reused again. The concrete will go into [construction] aggregate and the steel will go to foundries for re-melting.”

Numerous Tshwane Emergency Services vehicles and police officers were at the cordoned-off area as the tall building tumbled down in a loud implosion.

According to the public works department, the HG de Witt building was bought by the department in 1984 and used as single living quarters for members of the South African Police Service.