The Russian invasion changed everything. The normal angst of teenage years, and the first ventures of independence, it all now takes place amid the ruins of a mostly deserted city. With danger ever-present, the 9 p.m. curfews are enforced not by parents, but by soldiers at checkpoints.

Parents are desensitized to the air raid sirens, and in any case feel they have no option but to let their children out for walks after endless time indoors. War has not cured ennui.

The teenagers stopped at a favorite hangout, the steps of a shuttered movie theater near a park where the lawn was pocked with shell craters. They gravitated to the empty bleachers of a soccer stadium, where no games are held lest a crowd form, inviting a more tragic outcome from a single rocket strike.

“There used to be more people, more shops, more cafes, concerts, cool holidays,” lamented Daria, 15, sitting in the bleachers, looking at the empty field.

“I miss my city without damage,” Denys said. “I miss my calm life. I miss security.”

They laugh, he said, but without joy.

“What else can we do, cry?” said Daniil.

After months of practice, he said, he can very accurately gauge from the boom the distance to a strike.