On any given day, Warszawa Centralna railway station, located in the heart of Poland’s capital city, can convey passengers across the country, or to international destinations as far away as Paris, Berlin, Vienna, Prague, Budapest — or even Kyiv and Moscow.

But since Russia invaded Ukraine last month, Warsaw Central train station, as it’s known in English, has seen a steady stream of Ukrainian refugees fleeing their homes — carrying bags full of their possessions, seeking aid as they flee from Russia’s incursion.

Ukrainian refugees pick up donated food and hygiene and baby care products at the Warsaw Centralna train station, in Poland, Wednesday, March 16, 2022. (AP Photo/Czarek Sokolowski)

Inside, a woman walked around with a handwritten sign that reads, “I’m from Ukraine. Please help.”

It’s a sign of what the United Nations calls the worst refugee crisis since World War II.

One month since the start of Russia’s invasion of Ukraine, almost a quarter of the country’s population of more than 44 million has been displaced, according to the United Nations.

Over 10 million people have been forced to flee their homes and leave everything behind, according to the U.N. refugee agency. Of that figure, more than 6.5 million are displaced within the country, and 3.7 million have fled Ukraine’s borders. 

No nation has taken in more refugees than Poland: More than 2 million Ukrainians have fled across the border to their neighbor to the west, leaving everything behind in fear for their safety.

The station in Warsaw has been transformed: Volunteers in bright vests aid refugees with everything from information to translation, or even a cup of coffee. Bins full of stuffed animals are provided for children.

Soft toys are provided for children, who have fled Ukraine, at the train station in Warsaw, Poland, Sunday, March 13, 2022. (AP Photo/Czarek Sokolowski)

There are signs for phone chargers, medical care and messages of encouragement. Outside, Celebrity chef José Andrés’ World Central Kitchen provides thousands of meals a day to those in need.

There’s even a man in a giant Tyrannosaurus rex costume handing out candy and treats to refugee children, trying to make them smile through a tough time.

A woman plays with her child, who sits on an air mattress, at the train station in Warsaw, Poland, Sunday, March 13, 2022. (AP Photo/Czarek Sokolowski)

Every day, train after train brings new refugees, thousands upon thousands of people seeking safety from Russia’s invasion.

One of them is Joseph Nichols, an American who arrived with his wife after a four-day journey from Ukraine. 

“We were lucky,” Nichols said, telling Spectrum News that he was in the U.S. when Russia invaded, but rushed back to Ukraine after their home was destroyed by the fighting.

“Gone,” Nichols said. 

Nichols and his wife plan on moving on from Warsaw to a “more quiet” place in Poland for a few weeks — signs inside the train station urge refugees to travel to smaller cities, saying the larger ones have become “overcrowded.”

“Big cities in Poland are already overcrowded,” one sign in the station reads. “Don’t be afraid to go to smaller towns: they are peaceful, have good infrastructure, and are well-adapted.”

Authorities in Poland have been providing free transportation to get to other European Union countries, including eight special trains per day traveling directly to Germany, according to one official.

Despite the danger, leaving everything behind is a difficult decision.

“It’s not an easy choice for the millions of people,” Nichols told Spectrum News. "You know, family, friends, language, culture. A lot of them are going back already.”

As for Nichols? “No, no.”

On Friday, President Joe Biden landed in Poland to be briefed on the humanitarian crisis and to announce $1 billion in additional aid. On Saturday, he will meet with Ukrainian refugees, after announcing this week that the U.S. will welcome as many as 100,000 Ukrainians into the United States.

The volunteers at Warsaw’s train station are a stark reminder of how much aid is still needed.

But for some, their presence makes all the difference.

“The volunteers here in Poland — the help given is remarkable, just fantastic,” Nichols said. “People smiling, helpful, no questions asked.”

“It would be a mess if those weren’t doing what they’re doing,” he added.

Women take care of children as they sit with their possessions at the train station in Warsaw, Poland, Sunday, March 13, 2022. (AP Photo/Czarek Sokolowski)