Six weeks after Spain and Portugal suffered a massive power outage, authorities in Madrid issued an official report on Tuesday saying April's cascading blackout that left tens of millions disconnected in seconds was caused by technical and planning errors that led to the grid's failure.
Spain's Ecological Transition Minister Sara Aagesen, who manages the nation's energy policy, said in a press conference that small grid failures, concentrated in the south of Spain, led to a chain reaction among larger ones.
