Russia’s war on Ukraine sparked the biggest refugee crisis this century. We meet some of the families torn apart.

Kyiv, Ukraine — President Biden was in Poland on Tuesday after visiting Ukraine to mark one year since Russia launched its full-scale invasion. Poland is one of several European nations that have been on the receiving end of an exodus of Ukrainians fleeing the war — an exodus the United Nations calls the largest refugee crisis of this century.

As thousands fled their homes, harrowing images beamed around the world from Kyiv’s central train station, showing lines of refugees miles and miles long, all waiting to escape across their country’s borders into an uncertain future, and amid freezing temperatures.

Families have been torn apart, some never to be reunited again.

We caught up recently with some of those who were forced to leave their homes by Russian President Vladimir Putin’s unprovoked assault — people displaced in the biggest and fastest mass-exodus of humanity since World War II.

According to U.N. figures more than 8 million people have fled the country while another 8 million escaped to safer places within Ukraine, though a significant number have since returned to their homes.

Some of the early predictions in the war were dire, with analysts speculating that Kyiv would fall within three days, and the entire country within weeks.

Trains at Kyiv’s central station overflowed for days as the sheer speed and scale of the invasion triggered a mass panic, with hundreds of thousands of people fleeing for their lives.

But today, despite almost a year of brutal warfare, Kyiv’s train station remains a fully functioning transit hub, and many of those who left have felt safe enough to come back home.

One of the first cruise missiles to pierce the heart of Ukraine’s capital tore a hole through a high-rise apartment building. We rushed out to report on it — to witness the damage to property, and to people.

We returned to find a lot of the damage had been repaired, and we spoke with Tatyana Leshchuk, who could have lost more than her apartment.

She showed us what used to be her 10-year-old daughter’s room, destroyed by the Russian missile, and described how her daughter had gotten up early that morning and was in the hall rather than her bed. It may have saved her life.

The blast forced the carpet to curl up over their heads, protecting them from glass and debris.

“I think God would bless us,” Leshchuk told CBS News.

She and her family fled to Bulgaria shortly after, but they’ve since returned to Kyiv, though they now live in another apartment.

The suburb of Bucha was hit particularly hard, and when Russian forces advanced on it, Eugene Lopatin’s family was trapped.

“Some people who were trying to escape on the first days, they were just killed inside their cars,” he recalled. “We were terrified to do it.”

Risking it on foot with a seven-year-old daughter and an eight-month-old baby son wasn’t an option either.

“The bridge between Bucha and Kyiv was destroyed, and there was no way to escape to Kyiv,” he said.

Finally, his family made a run for it in a convoy with friends, and they made it to the Polish border. Men of fighting age like Lopatin were needed on the battlefield, however, and weren’t allowed to leave, so families embraced one another — some for the last time.

Lopatin has since been reunited with his family, but he’ll never forget what he told his daughter on that day when he said goodbye.

“That I love her and that we will see each other someday, and everything will be okay, don’t worry,” he told CBS News. “And I told her that light always beats the darkness. Those were my words.”

Lopatin told us he immediately volunteered to fight, but he eventually returned to his neighborhood in Bucha after it was liberated, where he joined UNICEF to help local children.

He said it made it easier to cope as he still misses his own family, who are staying on safer ground.