An American citizen was among at least 28 people killed in a large-scale Russian drone and missile strike on Kyiv that began Monday night and continued into Tuesday morning, Ukrainian authorities confirmed.

The victim, 62-year-old Fred Grandy, had traveled to Ukraine to assist in post-attack cleanup efforts. Grandy, an artist from Franklin, Virginia, arrived in Kyiv in late May. Family members said he was motivated by frustration over what he saw as the United States pulling back its support for Ukraine.

“He was a person who wanted to make a difference so badly,” said his sister, Sietska Reed, 75, to the New York Times. “He told me that he felt he was right where he should be.”

The attack that killed Grandy was one of the largest air assaults on Kyiv since the war began. Emergency crews continued to search the rubble on Wednesday. Much of the destriction occurred in a residential area in western Kyiv where a nine-story building was nearly destroyed.

Ukrainian officials said Grandy died from shrapnel injuries. The State Department confirmed Tuesday that an American citizen had been killed in Ukraine but did not immediately release a name at the time, according to Reuters. Ukrainian authorities later confirmed the individual was Grandy.

The Russian Defense Ministry claimed responsibility for the attack, stating that “all designated objects” had been hit, though it did not acknowledge civilian casualties. Russian strikes have intensified in recent weeks, further undermining any remaining prospects for a cease-fire.

According to United Nations figures, more than 13,300 Ukrainian civilians have died since Russia’s full-scale invasion began in February 2022. Grandy, who once created handmade signs and metal flowers, had recently sold his home in Virginia and traveled through several European countries before entering Ukraine.

His sister said he was working with a local charity, though the organization was not identified. “He thought, you just don’t let a bully do that stuff, and you don’t just abandon people,” Reed said. “And he just believed that people need a hand up.”