Millions of people in Spain, Portugal and parts of southern France lost power on Monday following a "severe disruption" in the European electrical system, the Spanish prime minister said. The cause of the disruption is still unknown,

Play was halted at the Madrid Open tennis tournament, while the Spanish capital's metro system ground to a stop.

Millions across Spain, Portugal, and parts of France were thrown into chaos Monday after a massive power outage — blamed on a “rare atmospheric phenomenon” by some officials— crippled transportation networks,