Following the massive power outage in Spain and Portugal in April, an investigation report released on Tuesday revealed that the blackout was caused by a power surge. The power surge on April 28 triggered a chain reaction of protective shutdowns,

Several' technical causes contributed to the event, ministers have said.

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,