A worker has been airlifted to hospital after falling through a skylight at Harrow Council's Central Depot in Forward Drive, Wealdstone.
The 30-year-old, employed by National Grid Gas (formerly Transco), fell approximately 20ft from the roof of a warehouse at 11.20am today (Wednesday) while installing a rooftop gas main.
London Ambulance Service despatched a fast response car and the capital's air ambulance to the scene and the victim was taken to the Royal London Hospital, in Whitechapel, to be treated for a broken leg, a broken arm and broken ribs.
Specialists from the Health and Safety Executive (HSE) were expected to arrive on site this afternoon to probe the circumstances of the incident, which took place in a building leased by the council to a contractor.
A spokesman for Harrow Council said: "We will obviously be co-operating fully with the HSE investigation into the cause of this accident."