A giant fire near one of the world’s busiest airports knocked out power, and the cause was under investigation. Hundreds of flights were canceled or rerouted, and analysts said disruptions could last days.

More than 1,300 flights were affected after a fire at a nearby electrical substation. Hundreds of thousands of passengers were stranded around the world.

Hundreds of thousands of people are impacted by the fire near London’s Heathrow. How long will the disruptions last and when will the airport reopen? Here’s what we know so far Flights to and from London’s Heathrow Airport were canceled Friday after a fire at a nearby substation knocked out power to Europe’s busiest airport,