The Spanish power distributor calls it “exceptional and extraordinary.” Power went down just after noon and by nightfall only half of the power had been restored in Spain. The cause was not immediately clear Monday.

Spain and Portugal declared a state of emergency after an all-encompassing power failure struck those nations as well as Belgium, Andorra and France.

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