The chairwoman of Spain’s power grid operator made a staunch defense of the company’s performance and refused any responsibility in the historic blackout that left the country without electricity for hours on Monday.

Millions were plunged into darkness in Europe on Monday as a massive power outage impacted parts of Spain, France and Portugal. The blackout wreaked havoc on travel across the three countries, and the impacts extended beyond there, too.

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.