BARCELONA, Spain (AP) — A blackout brought much of Spain and Portugal to a standstill Monday, halting subway trains, cutting phone service and shutting down traffic lights and ATM machines for the 50 million people who live across the Iberian Peninsula.

A countrywide power outage impacted Spain—as well as swaths of Portugal and smaller portions of France—Monday afternoon, affecting essential services and wreaking chaos across the Iberian Peninsula. The cause of the outage is currently being investigated by Spanish and Portuguese officials and ministers.

According to Spain’s meteorological agency, AEMET, temperatures across the country were between 60 and 70 degrees Fahrenheit around the time of the power outages. By the end of the day, highs had climbed to between 82 and 87 degrees.