BERLIN—More than 120 people have died in devastating floods across parts of western Germany and Belgium, officials said Friday, as search and rescue operations continued for hundreds more still unaccounted for or in danger. Authorities in the German state of Rhineland-Palatinate said 60 people had died there, including 12 residents of an assisted living facility for people with disabilities in the town of Sinzig who were surprised by a sudden rush of water from the nearby river Ahr. In neighboring North Rhine-Westphalia state officials put the death toll at 43, but warned that the figure could increase. German President Frank-Walter Steinmeier said he was “stunned” by the devastation caused by the flooding and pledged support to the families of those killed and to cities and towns facing significant damage. “In the hour of need, our country stands together,” Steinmeier said in a statement Friday afternoon. “It’s important that we show …