By **Todd Symons** and **Alex Stambaugh**, CNN
Heathrow Airport. Photo: 123rf.com
London's Heathrow Airport, one of the world's busiest, will be shut all day Friday due to a "significant power outage" as a result of a large fire nearby, airport officials said.
"Due to a fire at an electrical substation supplying the airport, Heathrow is experiencing a significant power outage," Heathrow Airport said in a statement on X.
"To maintain the safety of our passengers and colleagues, Heathrow will be closed until 23h59 on 21 March."
London Fire Brigade said a transformer within the substation was alight with 10 fire engines and around 70 firefighters responding to the blaze.
"Firefighters have led 29 people to safety from neighbouring properties, and as a precaution, a 200-metre cordon has been established, with around 150 people evacuated," Assistant Commissioner Pat Goulbourne said in a statement.
Passengers are advised not to travel to the airport and should contact their airline for further information, it added.
**_\- CNN_**