what distrubing news did Michael Holtzapfel bring to Himmel street? why did this news devastate Rosa Hubermann as well as his own mother?

Michael has just returned from the Battle of Stalingrad. Liesel lights a cigarette for him. Michael informs Rosa that his brother died in a makeshift hospital; he also tells her that he heard Hans Junior is alive there.

Death explains how Michael's brother Robert died: on a freezing cold January day in Russia, Robert's legs were blown off. He was brought to the temporary hospital and died three days later, his brother at his side. At Frau Holtzapfel's home, Liesel reads to Michael and his crying mother.