Yandex says drones hit a second data center in two days, knocking Kaluga modules offline
In brief
- Kaluga data center, Yandex's largest, had modules disabled by a drone attack, the company said.
- Kaluga strike followed an October 8 attack on Yandex's Sasovo facility in the Ryazan region.
- Sasovo attack caused a fire and stopped operations completely, Yandex said.
- Yandex reported no casualties and hasn't given a timeline for Sasovo's return.
- Zelensky characterized the strikes as retaliation for Russian attacks on Ukrainian data centers.
Two sites in two days
Sasovo was hit first. Yandex said that attack caused a fire and stopped operations at the site completely, according to Crypto Briefing's report. The company hasn't given a timeline for when the site will return to service.
Kaluga came next. It's Yandex's largest data facility (about 130,000 square meters, more than 3,800 server racks and a design capacity of 63 megawatts), and Yandex said modules there were knocked offline.
Yandex reported no casualties from the attacks.
Kaluga Governor Vladislav Shapsha said nine people were injured in regional drone strikes on the nights of October 8 and 9. He didn't say whether any of those injuries were connected to the Yandex site.
What sits inside Sasovo
The Sasovo facility houses two of the three supercomputers Yandex uses to train YandexGPT, its flagship AI model, Crypto Briefing reported. The machines are named Lyapunov and Chervonenkis. That's two-thirds of the YandexGPT training supercomputers sitting at a site Yandex says isn't operating.
The fallout wasn't limited to Yandex's own AI work. Major clients, including Russian Railways and mobile operator MegaFon, were affected after the Sasovo attack, according to Crypto Briefing. The same report said Yandex shares fell about 4% on the Moscow Exchange after news of the second attack.
Zelensky's framing
Ukrainian President Volodymyr Zelensky described the drone strikes as retaliation for Russian military actions targeting data centers in Ukraine. That's his characterization of the attacks.
For now, Yandex hasn't said when Sasovo will come back online.
Frequently asked questions
Which Yandex data centers were hit by drones?
Yandex said drones hit its facility in Sasovo, in the Ryazan region, on October 8 and its Kaluga data center, with the Kaluga incident confirmed on October 9, 2026. Kaluga is Yandex's largest data facility. LeoDex News couldn't independently verify the company's accounts.
Why does the Sasovo data center matter for YandexGPT?
According to Crypto Briefing, Sasovo houses two of the three supercomputers Yandex uses to train YandexGPT, its flagship AI model. The machines are named Lyapunov and Chervonenkis. Yandex said the attack stopped operations at the site completely and hasn't given a timeline for its return.
