Heathrow Airport said it expected “significant disruption" over the coming days due to the power outage caused by the fire at a nearby electrical substation. The airport had previously said it would be shut until at least midnight local time, with no flights leaving today.

The blaze forced Britain’s largest airport to cancel or divert more than 1,000 flights on Friday and removed a linchpin of global air travel. Counterterrorism police were investigating the cause of the fire.