Electricity has returned to most of Spain and Portugal but with continued disruptions on the second day after an unknown failure caused a massive blackout across much of western Europe.

The blackout that engulfed the Iberian Peninsula on Monday was chaotic and stressful for many. But it had a silver lining.

Renfe, Spain's national railway company, said on social media that the "entire national electricity grid was cut off" at 12:30 p.m. local time. It brought parts of Spain and Portugal to a standstill,