Thousands evacuated from City offices after gas main ruptures on Old Broad Street
A six-storey office block on Old Broad Street has been evacuated and around 4,700 people moved from surrounding buildings after a gas main ruptured in the heart of the City of London. A 200-metre cordon was thrown up between Threadneedle Street and London Wall as firefighters dealt with the leak.
The London Fire Brigade was first called at 10.56am. Crews arriving on Old Broad Street found a ruptured six-inch gas main at the office building and ordered the evacuation as a precaution. Two fire engines from Dowgate and Shadwell fire stations attended, along with a fire rescue unit from Bethnal Green, and crews remained at the scene into the afternoon.
The evacuation unfolded through the middle of the working day, emptying offices in one of the busiest business districts in Europe. Workers poured onto pavements as the cordon went up, with nearby buildings cleared one by one while firefighters worked to make the area safe. No injuries were reported.
Road closures and bus diversions
Wormwood Street was closed first as the scale of the leak became clear, cutting off a key route through the eastern City. Bus services running through the area were diverted around the closures, leaving commuters to find alternative routes during the lunch-hour rush.
The 200-metre exclusion zone stretched between Threadneedle Street and London Wall, sealing off streets normally packed with office workers, delivery vehicles and buses. Police assisted with traffic management as the closures took hold.
Commuters heading into the Square Mile were urged to avoid the area and check their journeys before travelling. The disruption came at one of the busiest times of the working day, with thousands of people already at their desks when the evacuation order came.
How the leak happened
Gas network operator Cadent said the pipe had been severely damaged by a private construction team working in the area. A spokesperson stressed that the work which caused the damage had nothing to do with Cadent or its pipework.
Damage to underground pipes by third-party construction work is one of the most common causes of serious gas leaks in central London, where Victorian-era infrastructure runs beneath streets that are constantly being dug up for building projects.
Cadent engineers kept a street closure in place on Great Winchester Street while repairs to the broken pipeline were completed. The company worked alongside firefighters through the afternoon to isolate the damaged section and make the area safe before allowing people back in.
Stand-down and return to normal
By the afternoon the Fire Brigade had lifted its cordon and people were being allowed back into the affected properties. The evacuation, while large, was carried out as a precaution and the leak was brought under control without any injuries or wider danger to the public.
The incident is a reminder of how quickly a single damaged pipe can paralyse a slice of the capital. With around 4,700 people evacuated, offices emptied and buses rerouted, the morning’s rupture turned an ordinary Tuesday in the City into a major emergency response.
Gas leaks of this scale trigger a standard multi-agency response: firefighters establish the cordon and assess the immediate danger, the gas network operator isolates the supply, and police manage the road closures. Rest centres are set up where residents are affected, though in this case the buildings cleared were almost entirely offices.
Engineers will continue monitoring the repaired main in the coming days. Anyone who smells gas is advised to call the national gas emergency number immediately, open windows, and avoid using electrical switches or naked flames.
