Spanish authorities say the massive power outage in April across Spain and Portugal was due to technical and planning errors that led to a cascade of failures in the grid.

Spanish investigators on Tuesday released a report showing that a power surge caused an hours-long blackout on the Iberian peninsula in late April. The power surge triggered a chain reaction of protective shutdowns,

Aelec, which represents Spain's main electricity companies including Iberdrola and Endesa, said on Wednesday that "claiming everything was done correctly" while blaming some power