London Fire Brigade crews were called to a demolition site on the junction of Portugal Street and Serle Street in Aldwych shortly after 4pm yesterday afternoon (20th April).
Specialist contractor Keltbray was bringing down the six-storey building when part of the structure and the scaffolding surrounding it suddenly collapsed.
Keltbray had been using the top-down method of demolition.
Around 100 people were evacuated from the building site and a further 100 people were evacuated from neighbouring properties. The latter will remain evacuated until structural checks have been carried out.
Fire Brigade station manager John Snelgrove, who was at the scene, said: "When the first crews arrived they found the building, which was under refurbishment, had collapsed between the fifth and second floors.
"Firefighters gave first aid to an injured man on site until ambulance crews arrived and also helped police put safety cordons in place and to evacuate people from the immediate area."
Neighbouring buildings evacuated until structural checks
It appears that a lot of people had a narrow escape. The one injured worker was taken to hospital with head and arm wounds described as 'non life threatening injuries'.
An eyewitness told the BBC: "There was a lot of dust but I could see there was a digger down amongst the rubble and one or two builders were running around trying to get someone out of the digger. The operator seemed to be trapped in the digger.”