Spain woke to news of Prime Minister Sánchez's brother being indicted for influence peddling and prevarication, along with first-quarter unemployment data showing the largest rise since 2013, with 92,500 jobs lost and unemployment climbing to 11.4%.

These stories were overshadowed at 11:00 AM when an unprecedented nationwide blackout struck Spain and parts of Europe. The outage, which eventually affected 15 countries, was caused by the sudden loss of 60% of the electric supply (15 gigawatts) within five seconds. Prime Minister Sánchez convened two emergency National Security Council meetings, declaring he would not rule out any hypothesis regarding the cause.

By evening, Interior Minister Marlaska declared a national emergency in eight communities as power was gradually restored. After nine hours, only about 50% of electricity demand had been met, with Red Eléctrica warning full restoration would take many more hours.