A video captured residents cheer and clap as power was restored to a neighborhood in Madrid following a 9-hour outage in most of Spain and Portugal. "The lights returning in the Pilar neighborhood is celebrated more than a goal from Iniesta,

Red Eléctrica, Spain’s electricity grid operator, ruled out a cyberattack, human error or unusual weather. Experts say it could take weeks to determine the cause.

An unprecedented blackout brought much of Spain and Portugal to a standstill Monday, stranding thousands of train passengers and