A massive power outage has knocked out electricity across huge parts of Spain and Portugal, shutting off traffic lights and causing chaos at airports, train stations and on the roads.

Power outages left tens of millions of people in Spain and Portugal in the dark on Monday. The blackouts shut off phone service and traffic lights, stopped trains, and cut off water access for U.S. Open champion Coco Gauff following her win at the Madrid Open, along with countless others.

It may take a week for the network servicing both countries to be fully repaired. Meanwhile, millions are without power.