All of Crimea lost power for 90 minutes today. What the heck happened?

On July 28, around 2 p.m., the entire Crimean peninsula lost power. At exactly 1:55 p.m., all four lines of the so-called energy bridge that connects Crimea to Russia’s Krasnodar region suddenly shut off. Crimean Fuel and Energy Minister Vadim Belik says this resulted in the entire peninsula losing electricity, creating a roughly 1,000-megawatt power shortage. “There’s no electricity at all in Simferopol. The traffic lights and everything else have stopped working,” a spokesperson for the Crimean government told Meduza after the public learned about the mass blackout. Even the trolleybuses stalled in place.

The reason for the power failure was an accident in the Krasnodar region. According to Russia’s Energy Ministry, the electric transmission lines to Crimea were disabled automatically when temperatures on the mainland reached 39 degrees Celsius (102 degrees Fahrenheit), triggering emergency shutoff measures.

The blackout did not affect the airport in Simferopol or “critical public facilities.” Airport officials told Meduza that they never lost power, due to the fact that its electricity is supplied by a local hydroelectric station. “We’re operating normally,” a representative for Simferopol airport said. Regional officials from Russia’s Emergency Management Agency confirm that the power outage had no effect on vital public services or heavily trafficked facilities, which were transferred to emergency backup generators.

Some spa resorts in Crimea suspended operations during the blackout. A spokesperson for “Kurpaty,” one of the peninsula’s biggest health spas, told Meduza that its electricity failed at 2 p.m. and was still out by 4 p.m. “Nizhnaya Oreanda,” another Crimea spa, told Meduza that it worked through the power outage, switching over immediately to a backup generator: “It’s the first blackout this year, but we’re ready for it.”

Crimea’s electricity supply started returning after an hour. By roughly 3 p.m., two of the four lines on the peninsula’s energy bridge had been restored. Speaking to Meduza, officials from Krymenergo confirmed these reports, adding that some consumers were already getting their power back at this stage. At the time of this writing, all four lines of the energy bridge are working again and the power supply has been restored completely.

The July 28 outage marks the first major electricity disruptions in Crimea since Russia’s energy bridge went online in May 2016. Before this, Crimea relied on Ukraine for its power supply, frequently suffering outages and interruptions. From December 2015 to May 2016, the peninsula endured a state of emergency, following Ukrainian activists’ attacks on several electric transmission towers feeding Crimea. The activists also blocked repair efforts.