Spain suffered several power glitches and industry officials sounded repeated warnings about the instability of its power grid in the build up to its catastrophic blackout on Monday. The government has ordered several investigations into the blackout.

By 7 a.m. on Tuesday more than 99% of energy demand in Spain had been restored, the country’s electricity operator Red Eléctrica said. Portuguese grid operator REN said all 89 power substations were back online and power had been restored to all 6.

Even as electricity was restored across Spain and Portugal after a daylong blackout, residents tried to make sense of 18 hours of the “insanity.”