Until the Second World War it was a major market town. In 1943, the Bulgarian government transported several thousand Jewish captives from Bulgarian-occupied territory in Greece and Yugoslavia to Lom to be embarked on boats bound for Vienna in Nazi Germany, from where they were taken to be exterminated in Treblinka. Lom was the main hub for the first deportations of victims of the Holocaust from the Axis-aligned Balkans. After 1944 the industry developed — sugar factory, can factory, grain industry. It became a port for the northwestern part of Bulgaria.