Cartagena, Spain - April 29, 2025 On April 29, X user Tina X shared a video showing residents in the Cartagena neighborhood celebrating the return of electricity after a major blackout. The footage captures lights coming back on and people cheering and shouting from their homes in excitement. Tina X wrote: “Momento en el que vuelve la luz en mi calle después de El Apagón.” Spain and Portugal lost most of their electricity early Monday afternoon. Shortly after 12:30 p.m. local time, Spain lost 15 gigawatts of electricity, which is about 60% of national demand, Prime Minister Pedro Sanchez said. Spain’s electric grid operator, Red Electrica de Espana, reported two major “disconnection events” before the blackout. The first event was resolved, but the second caused more serious damage, including interruptions from France’s electrical system. It led to what officials described as “a massive, temporary disconnection.” Three hours before the outage, power sensors in Madrid-area homes showed early signs of instability. Bob Marshall, CEO of Whisker Labs, said voltage fluctuations began around 9:30 a.m. local time. His company has sensors in homes in and around Madrid, testing technology for fire prevention and grid monitoring. Marshall said the data showed abnormal oscillations that increased in strength and frequency until the grid failed. By noon, voltage was jumping up and down by about 15 volts every 1.5 seconds. Marshall said, “The way I would interpret our data is that the grid is struggling. Something’s wrong. And it’s showing increasing signs of instability.”