"We're heading to Warsaw (hopefully). Train to Lviv was not an option," wrote Chmerkovskiy, who was in Ukraine to film as a judge for the country's version of World of Dance. "The situation at the train station is insane."
"I'm a big man with nothing but a backpack," Chmerkovskiy noted, calling the experience "traumatizing." Chmerkovskiy said he was in a train cabin with four adults and seven kids that normally holds three people.
"There's usually up to 30 people in this particular wagon," he wrote. "We were told we have to fit 135. Walkways are packed. People everywhere. It's sweaty and claustrophobic."
The former Dancing With the Stars pro added that watching a young boy "hysterically crying" as he said goodbye to his father "finally broke me."
Chmerkovskiy's wife, Peta Murgatroyd, reposted his update to her Instagram, writing, "@maksimc YOU CAN DO IT!!!!!!!! Get back home! I am so f**king proud of you for helping those kids on board!"
Later Chmerkovskiy shared a video update, noting that he was at a station about 30 minutes from the border of Poland.
"They stopped to change wheels -- can't make this up -- on our train," he said.
On Tuesday, Chmerkovskiy finally confirmed, "I'm in Poland." He included the Ukrainian flag, Polish flag and prayer hands emoji in his post.