U.K. government orders probe into Heathrow shutdown that sparked concern over energy resilience

Heathrow Airport fire causes chaos, raises questions about UK infrastructure resilience, with thousands stranded and flights cancelled.

The British government has ordered an investigation into the country's “energy resilience” after an electrical substation fire shut Heathrow Airport for almost a day and raised concerns about the U.K.'s ability to withstand disasters or attacks on critical infrastructure.

While Heathrow Airport said it was now “fully operational,” thousands of passengers remained stuck, and airlines warned that severe disruption will last for days as they scramble to relocate planes and crews and get travellers to their destinations.

Inconvenienced passengers, angry airlines and concerned politicians all want answers about how one seemingly accidental fire could shut down Europe's busiest air hub.

“This is a huge embarrassment for Heathrow airport. It's a huge embarrassment for the country that a fire in one electricity substation can have such a devastating effect," said Toby Harris, a Labour Party politician who heads the National Preparedness Commission, a group that campaigns to improve resilience.

Energy Secretary Ed Miliband said he'd asked the National Energy System Operator, which oversees U.K. gas and electricity networks, to "urgently investigate" the fire, “to understand any wider lessons to be learned on energy resilience for critical national infrastructure."

It is expected to report initial findings within six weeks.

“The government is determined to do everything it can to prevent a repeat of what happened at Heathrow," Mr. Miliband said.