UK Power Networks are the local network operator for London and the South East. The substation that has gone boom is a National Grid one, so it's presumably aff

UK Power Networks are the local network operator for London and the South East. The substation that has gone boom is a National Grid one, so it's presumably affecting things upstream of local substations. I'm surprised there's a single point of failure at this level though, you'd think Heathrow would be considered important enough to have multiple feeds at a national grid level.