There’s still no official explanation for the blackout in Spain, Portugal, and parts of southern France—but experts point to the makeup of the Iberian peninsula’s power grid.

The sweeping power outage that hit Spain and Portugal this week has raised questions about the electricity grid in a region not normally known for blackouts. Monday's outage, one of the worst ever in Europe,

Spain's investigation into the power outage that blacked out the entire Iberian Peninsula this week continued Thursday as top security officials met Wednesday.