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.

MADRID (AP) — The cause of Spain and Portugal’s widespread blackouts remained a mystery on Tuesday, with some isolated disruption remaining after power was largely restored to both countries.

At least three people died as a result of Monday's massive power outage on the Iberian Peninsula, according to reports. In the small town of Taboadela in north-west Spain, three members of a family died from carbon monoxide poisoning,