The hunt has begun for the cause of a massive blackout across Spain, Portugal and parts of France that halted trains, bank machines and traffic lights, in one of Europe's biggest ever power system collapses.

Red Eléctrica" data-has-syndication-rights="1" src=" /> Power went down Monday afternoon in vast areas of Spain, crossing over into Portugal and France, causing widespread outages in homes and businesses and bringing transportation infrastructure to a halt.