The whole of Spain, as well as parts of Portugal and France were affected by a massive power outage on Monday, April 28. Key cities including Madrid, Seville and Lisbon.

Parts of Madrid underground were evacuated and traffic lights in the city failed to work according to local media. In Valencia, the metro announced at the time that it had suspended service across the entire network.

Although Spain’s national grid operator ruled out a cyberattack, the High Court has opened a preliminary investigation into whether it could be classified as one, which would be considered as an act of terrorism. Prime Minister Pedro Sanchez has admitted that the exact cause is still unknown though he ruled out that of excess renewable energy.