Fire at Power Substation Sparks Airport Shutdown

March 24, 2025

The fire that led to Heathrow’s temporary closure originated at the North Hyde electrical substation in west London. It broke out late on Thursday night at approximately 23:23 GMT on Nestles Avenue, Hayes. Emergency responders, including the London Fire Brigade (LFB), rushed to the scene and battled the flames through the night, eventually bringing the fire under control by 06:28 GMT on Friday morning.

The blaze was particularly severe due to the involvement of a transformer containing 25,000 liters of cooling oil, which sustained the flames and produced thick, dark smoke. Large plumes were visible across the area, with videos shared on social media showing towering flames engulfing the facility. Residents in the vicinity were advised to keep their doors and windows closed to minimize exposure to smoke inhalation.

The cause of the fire remains under investigation, but early reports indicate that there is no evidence of foul play. The Metropolitan Police’s counter-terrorism unit is overseeing the inquiry due to the substation’s strategic importance as part of the country’s infrastructure. Specialist investigators are conducting detailed assessments, but officials have emphasized that, as of now, there is no indication of suspicious activity.

Energy Secretary Ed Miliband stated that the substation’s backup generator appeared to have been knocked out, exacerbating the power failure. National Grid engineers worked rapidly to reroute electricity and restore power to affected areas, but the disruption was widespread.

Impact on Heathrow Operations

As the UK’s busiest airport, Heathrow is a critical node for passenger travel and international cargo. The fire-induced power outage raised concerns about the airport’s backup power capabilities and overall resilience to infrastructure failures.

Reports suggest that Heathrow has backup systems, including diesel generators and uninterruptible power supplies, designed to maintain essential functions. However, restarting power across an airport of this scale is a complex process that takes time. While critical systems remained operational, the backup power was not sufficient to keep the entire airport running, necessitating a temporary shutdown.

Once electricity was restored, airport personnel had to meticulously reboot and test various systems before normal operations could resume. Experts have questioned why Heathrow’s contingency plans did not prevent such widespread disruption and whether the National Grid’s transmission network should have been capable of supplying emergency power.

At least 1,351 flights were affected on Friday, with 120 already in the air when the closure was announced. Travelers were urged not to proceed to the airport unless their airline specifically advised them to do so.

Impact on Flights and Residents

On Saturday, Heathrow confirmed it was fully operational again, but the aftereffects of the closure were expected to persist for several days. British Airways projected that 85% of its scheduled flights would take off but warned passengers to expect delays.

Several airlines have gradually resumed operations. Air Canada and United Airlines restarted limited flights on Friday evening, while Virgin Atlantic anticipated running a near-complete schedule on Saturday with only a few cancellations. Meanwhile, Gatwick Airport stated it was prepared to provide assistance if required. Qantas had to divert multiple flights from London to Paris, and further disruptions were expected.

British Airways canceled all short-haul flights scheduled for Friday. However, select long-haul flights—including those to Cape Town, Johannesburg, Singapore, and Rio de Janeiro—were permitted to depart from Heathrow starting at 19:00 GMT. Cathay Pacific also canceled all its London-bound flights on Friday. In addition, the Heathrow Express railway service is currently running on a reduced schedule between Paddington and the airport.

The fire not only affected Heathrow but also left thousands of homes in west London without electricity.

Approximately 16,300 homes experienced outages due to the substation failure, according to Scottish and Southern Electricity Networks (SSEN). Around 150 residents had to be evacuated from their homes as a precautionary measure. National Grid announced on Friday afternoon that engineers had successfully reconfigured the network, restoring power to all affected households and businesses, including Heathrow Airport.

Fortunately, no injuries were reported as a result of the fire.

Ongoing Investigation and Next Steps

Given the fire’s location and its impact on critical infrastructure, the Metropolitan Police’s counter-terrorism unit is leading the investigation, although there is currently no indication of foul play.

Specialist investigators from the fire service, energy regulators, and law enforcement agencies are continuing to assess the substation’s equipment to determine what caused the blaze. The London Fire Brigade is working closely with these agencies to ensure that similar incidents can be prevented in the future.

As investigations progress, further updates are expected regarding Heathrow’s contingency planning and whether additional safeguards will be introduced to prevent such large-scale disruptions in the future.