Europe's busiest -- shut down early on Friday after a major fire at an electricity substation cut power to the sprawling hub, causing disruption worldwide to hundreds of flights and thousands of travellers.

LONDON] Heathrow airport was completely shut down on Friday (Mar 21) after a power outage due to a fire at a London electricity substation, causing travel chaos for passengers around the world and the cancellation or diversion of hundreds of flights from Europe’s busiest air hub.

Britain's Heathrow airport, Europe's busiest, was shut down early Friday for 24 hours after a major fire at an electricity substation cut power to the sprawling facility west of London, officials said.