Police were called at approximately 12.45 today following reports of an electrical explosion on a building site at the junction of High Holborn and Drury Lane.
Officers, London Fire Brigade and London Ambulance Service are in attendance. One man believed to be in his 20s is being treated at the scene.
The Health and Safety Executive will be notified.
Road closures remain in place.
More top news
The Marsh & Parsons poster - captioned "a charming period property with a modern extension" - soon prompted criticism.
The track will be demolished to make way for a housing development and a new Stadium for AFC Wimbledon.
Just four authorities (Hammersmith & Fulham, Hillingdon, Newham and the City of London) have chosen to freeze council tax altogether.