The airport administration released a statement urging travelers to avoid heading to Terminal 4, confirming that ground staff are providing the necessary support to passengers, while the remaining terminals continue to operate normally.
They added that the first report was received at 5:01 PM local London time, and fire units from Feltham, Heathrow, and Wembley stations participated in the response.
The operator of Heathrow Airport in the British capital, London, had announced last March that after a fire broke out in a substation supplying it with power, leading to a significant power outage.
Heathrow Airport is one of the busiest airports in the world, having recorded a record 83.9 million passengers last year, with an aircraft taking off or landing every 45 seconds.
