London’s Heathrow airport will be shut for the entire day on 21 March, after it suffered a “significant” power outage from a major electrical substation fire.
In a post on X, the operator of London’s main gateway says the airport will be shut until 23:59 on 21 March “to maintain the safety of our passengers and colleagues”.
Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage.
— Heathrow Airport (@HeathrowAirport) March 21, 2025
To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March.
Passengers are advised not to travel to the airport… pic.twitter.com/7SWNJP8ojd
“Passengers are advised not to travel to the airport and should contact their airline for further information,” the post adds.
In a statement to FlightGlobal. Heathrow Airport says that while fire crews are responding to the substation fire, “we do not have clarity on when power may be reliably restored”.
Heathrow adds that it expects “significant disruption over the coming days”, but does not indicate when the airport will reopen.
Eurocontrol’s network operations portal indicates that the airport will be closed “until further notice” with diversion requests sent out to at least 11 airports, including to London’s Gatwick and Stansted, Paris’ Charles de Gaulle, as well as Amsterdam’s Schiphol airports.
Flight tracking site FlightRadar24 estimates some 120 flights are being impacted by the Heathrow closure so far. Flights are currently being diverted to neighbouring Gatwick, Amsterdam, Glasgow and Shannon.
According to the BBC, the fire broke out at a substation near the airport late on 20 March, with its cause not yet known. Firefighters have worked through the night to contain the fire, with around 150 people living in its vicinity evacuated safely.
