The UK Secretary of State for Energy Security and Net Zero Ed Miliband announced Saturday that he is ordering an investigation into the substation fire.

The airport said it had made space for extra flights, but it is expected to take days to get stranded passengers to their destinations and displaced aircraft into the proper locations.

Heathrow is open and “fully operational” after a massive fire at a nearby electrical substation shut down the airport and triggered chaos across global air travel, leaving a quarter of a million passengers stranded.