Luis, 29, said he served with the Mexican Army fighting drug cartels a decade ago, but until last week, he was an events photographer in Chihuahua City, Mexico, photographing mostly weddings. Then, scrolling through Reddit, he found an Associated Press photo showing an unidentified pregnant woman on a stretcher, being carried out by rescue workers after a Russian strike against a maternity hospital in Mariupol. Russian officials said Ukrainian forces had been using the hospital as a base and said the images were fake.

“I saw the face of my sister in that woman,” Luis said. “I do not have children yet, but I imagined how the baby’s father felt, how the woman and her family felt.”

He had never met a Ukrainian before flying to Europe. But when he read the woman and her baby had died, he decided to close his studio, sell his cameras and book the four flights to get to Poland, from where he drove across the border to Ukraine.