BUDAPEST, Hungary (AP) — An unprecedented blackout across Spain and Portugal upended the lives of millions across the Iberian Peninsula, a stark reminder of modern society’s reliance on electricity, and how quickly life can descend into chaos when the grid goes down.

Luis Ibáñez Jiménez was driving on a highway in east Madrid when Spain lost power. “Suddenly, there were no traffic lights,” the resident of the capital told CNN. Cars piled up, and nobody had right of way.