Two parents and their adult son are said to have died from carbon monoxide poisoning after using a generator during the blackout that hit Spain and Portugal this week, according to local reports.
This would bring the number of deaths linked to the incident, which struck the Iberian Peninsula around midday on Monday, to four.
Millions of people were caught up in the chaos triggered by the mass blackout.
Explained: What impact will blackout have?
It brought many areas to a standstill, stopping trains, grounding planes, halting internet and mobile phone services, downing traffic lights and cash machines and leading to some routine hospital operations being suspended.
Spain's interior ministry declared a national emergency and both it and Portugal convened emergency cabinet meetings over the issue.
Portugal's grid operator said the blackout was caused by a "rare atmospheric phenomenon" which caused "anomalous oscillations" in very high-voltage lines. But Spain's grid operator has so far not confirmed any possible cause.
Much of the power supply has now been restored.
Carbon monoxide poisoning
The elderly married couple and their son were reportedly found dead at their home in Ourense, in northwest Spain, around midday on Tuesday.
Local reports pointed to carbon monoxide poisoning as responsible for their deaths.
Europa Press, citing sources in the emergency services, said the couple were aged 81 and 77, and their son was 56.
It quoted local mayor Alvaro Vila as saying there were "indications" the poisoning came about due to faults from a generator used to keep a ventilator going.
When a care worker couldn't get access to the property, the civil guard and the fire department were called.
Fire in Madrid
A middle-aged woman was found dead Monday night after a fire in her first-floor Madrid apartment, according to reports.
It was initially reported that the main line of the investigation was over a candle starting the fire.
El Pais reported on the fatal blaze, saying it took place in the Carabanchel district of the Spanish capital.
Read more:
Spain and Portugal blackouts as it happened
Why restoring power will be a nightmare
It added that thirteen other people in the apartment building were treated by medics.
The first calls to emergency services were reportedly made shortly before 10pm local time.
(c) Sky News 2025: Couple and adult son 'died from carbon monoxide poisoning after using generator'
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