April 29 (UPI) — Electricity was restored to most of Spain and Portugal as of Tuesday, with continued disruptions on the second day after an unknown failure caused a massive blackout across much of western Europe.

Portugal and Spain remained under a state of emergency as power slowly became restored late Monday evening after the outage hit parts of France, Andorra and neighboring Belgium.

It brought life to a standstill, including elevators, traffic lights, business, roads, trains and hospitals. The power outages impacted Monday’s 2025 Madrid Open, forcing the suspension of matches, officials said.

On Tuesday, Spanish power company Red Electric said power had been 99% restored, but Spain’s transport minister warned that some rail trains may experience issues.

“The energy situation in Spain and Portugal is back to normal. This incident is the most severe for almost two decades in Europe,” European Commission Chief for Energy and Housing Dan Jorgensen posted on X, saying the commission stands ready to support Spain and Portugal “in all ways possible” and will “initiate a thorough investigation.”

Authorities mostly ruled out a cyberattack as the cause behind Monday’s chaos which left nearly 60 million without electricity with inquiries underway to pin down a cause.

“We have no information related to a cyberattack or a hostile act at this stage,” stated Portuguese government spokesman Antonio Leitao Amaro on Tuesday.

Amaro indicated that “there would seem to have been an issue in the power transmission network” in neighboring Spain, where the nation’s Interior Ministry deployed 30,000 officers for security concerns and roads where traffic signals were not working.

Spanish Prime Minister Pedro Sanchez said Monday night the power meltdown took place when 15 gigawatts of power was suddenly lost in five seconds, but experts say it could take weeks to figure out the actual cause.

“To give you an idea, 15 gigawatts is equivalent to approximately 60% of the country’s demand at that time,” said Sanchez.

Also on Tuesday, the Spanish head of state, King Felipe VI, sat down to chair a meeting of the national security council at Moncloa Palace in Madrid at the request of Sanchez.

Earlier on Monday, Portugal’s National Energy Network said it could take a week to return the full grid to normal.

Portugal’s Prime Minister Luis Montenegro also confirmed there was “no indication” it was caused by a cyberattack, saying “everything indicates” the cause of the outage “did not originate in Portugal.”

That was supported by Antonio Costa, the president of the European Council and a former Portuguese prime minister, who likewise backed up Montenegro’s claim that there were “no indications” of a cyberattack.

Meanwhile, Montenegro said that his government had requested an independent audit into the incident by the European Union’s Agency for the Cooperation of Energy Regulators.

“We want a full investigation of the outage’s causes,” he told reporters. “We need quick, urgent answers.”

Spanish grid operator REE mentioned Monday evening a “strong fluctuation in power flows, accompanied by a very significant loss of production” in the kingdom, where roughly 40% of its electricity arrives via solar or wind power.