What caused the fire that closed the Heathrow airport?
Investigators developed the burnt remains of a power sub -setting near the Heathrow airport in London on Friday, looking for the cause of a spectacular flame that closed the most crowded travel hub of Europe for most of the day and raised wider questions about British energy infrastructures.Energy officials and experts said that a defect in a transformer with 275,000 volts that crossed it probably aroused a huge oil -powered fire that interrupted the airport and tens of thousands of nearby houses from the electricity grid. The systems designed to prevent such a apparently failed fire and the size of the fire seemed to prevent a second transformer in the vicinity of restoring electricity.But the mystery of what caused that fault first remained far from resolved by the end of Friday, even if...










