Russian airstrikes targeted gas, electricity and other key infrastructure across Ukraine on Thursday, knocking out heating and water supplies to a huge number of civilians just as winter sets in. As snow started falling around the country, President Volodymyr Zelenskyy said Vladimir Putin's tactics had left more than 10 million Ukrainians without electricity.

That includes many residents in villages, towns and cities recently liberated from months of Russian occupation in eastern and southern Ukraine. The people of Kherson, a major southern city that Russia's invading forces only fled a couple weeks ago as Ukraine's army advanced, are now staring down a winter without power, having already endured so much.

But right now, there's still jubilation. Not since American troops helped defeat the Nazis has Europe seen celebrations quite like what Kherson is experiencing now.

And only now, seeing what the Russians left behind when they made their hasty retreat, is it clear just why.

The instruments of what survivors say was torture at the hands of the invaders still litter a police station in Kherson. Residents and Ukrainian officials have said Putin's troops turned it into a "torture chamber," and the air is still tinged with smoke.

Oleksander, a survivor, said some of his fellow detainees at the old police station were electrocuted.

"My cellmate's tongue was so black and swollen after interrogation, he couldn't put it back in his mouth," he said.

Vitaly and Alesha said they were blindfolded and then taken into a basement after relaying intelligence to Ukrainian forces.

"Around my kidneys, over here, they kicked me, and they punched me in the face until my nose was bleeding" said Alesha. "They even said they would force us to walk through a minefield towards Ukrainian positions."

The Russian troops have retreated, but they're still within earshot, just across the Dnipro River. The river now forms the front line between Ukraine's defenders, who have retaken ground and pushed right up to its western bank, and the occupiers, who have dug in on the other side.

That leaves the city of Kherson, on the west bank of the river, and all of its people still within range of Russian-controlled cell phone towers — not to mention its artillery, and even gunfire.

In addition to traumatized survivors, the Russian retreat has also left behind mass graves.

Ukraine's chief investigator said the bodies in one Kherson gravesite all bore signs of torture.

Dmytro Lubinets, the Ukrainian parliament's human rights commissioner, said more than 3,000 crimes were committed during Russia's months-long occupation of the Kherson, and 90% of them were war crimes, including rape, torture, and murder.

Ukrainian media quoted Interior Minister Denys Monastyrsky as saying, meanwhile, "that the search has only just started, so many more dungeons and burial places will be uncovered."