A massive Russian attack that set apartments alight and knocked out heating to thousands in Ukraine’s southern port city Odesa killed one person and wounded 10 others, authorities said Friday.

The Thursday night strikes on the Black Sea city damaged residential buildings, the heating system, churches and educational institutions, according to Odesa Mayor Gennadiy Trukhanov, who said it had been “a massive combined enemy strike.”

Trukhanov said early Friday that a 35-year-old woman sleeping near a window at the time of the attack had died.

The State Emergency Service of Ukraine confirmed one death and said another 10 people were wounded, including two children.

Fires broke out in several places but were quickly extinguished, while the main heating pipeline was damaged, leaving tens of thousands in the cold as nightly temperatures plunge to freezing.

“More than 40,000 people (as well as) medical and social institutions are without heating,” Trukhanov wrote on Telegram. “Generators and heaters are working in medical institutions.”

The mayor’s office said hot drinks and blankets were being distributed while the pipeline was repaired.

After fleeing during the air raid siren, Odesa resident Oleksandra said she saw pictures of her damaged home.

“When everything happened, we were hiding in a shelter. We saw that this was our house in the photos from the local channels,” she told public broadcaster Suspilne Odesa.

Russia has recently stepped-up aerial attacks on southern Ukraine, damaging civilian vessels and port facilities in the Odesa region, while Kyiv has intensified its attacks on Russian military and energy targets.

Early Friday morning, Ukraine’s air force reported six Tu-95 bombers — which are capable of carrying cruise missiles — heading southeast from a base in Russia.

Moscow’s Ministry of Defense meanwhile announced it had intercepted 51 Ukrainian drones overnight, thwarting an attack that had targeted coastal regions, including over Crimea and the Sea of Azov.

Ukraine is bracing for its toughest winter of war yet, with Moscow having destroyed swathes of its generating capacity and continuing to strike energy sites.

In previous winters, millions of Ukrainians endured regular blackouts and lost heating in sub-zero conditions.

Ukrainian forces are losing ground in the east and concerns are mounting in Kyiv over the future of foreign military aid after the victory of Donald Trump in the United States presidential election.

Kyiv has for months been appealing to its Western allies to provide more air-defense systems to fend off Russian attacks on cities and critical infrastructure.