Spain and Portugal are reeling from a massive, unexplained power outage that knocked out traffic lights, caused chaos on roads and in airports, and prompted both countries to declare a state of emergency.

A blackout has brought much of Spain and Portugal to a standstill, affecting millions of people. The Spanish power distributor calls it “exceptional and extraordinary."

See photos of the massive power outage that affected millions of people in Spain and Portugal due to an "induced atmospheric vibration."