Power was gradually restored for millions on Monday following what Spanish officials called a "rare atmospheric phenomenon."

A massive power cut hit large parts of Spain and Portugal on Monday, causing widespread chaos and disruption. The outage left millions of people without electricity, while internet and phone networks were also down.

A blackout brought much of Spain and Portugal to a standstill Monday, halting subway and railway trains, cutting phone service and shutting down traffic lights and ATMs for millions of people