What happens to Arthur Berg in Cologne? Be specific.

After Arthur and his family moved to Cologne, the city was bombed. Arthur's sister died in his arms.

A SMALL TRIBUTE TO ARTHUR BERG, A STILL-LIVING MAN

The Cologne sky was yellow and rotting, flaking at the edges. He sat propped against a wall with a child in his arms. His sister. When she stopped breathing, he stayed with her, and I could sense he would hold her for hours. There were two stolen apples in his pocket.