World War II broke out on 3 September 1939. On 7 May 1940, it was reported to the department that all tools and effects from the depôt at Saint-Martin-Boulogne had disappeared apart from the largest items. All six locomotives were in the depôt, but had been stripped of valuable metals such as copper. The wagons had been broken up and all wood removed. Only one lorry remained. The job of compiling a full inventory hampered by the fact that the depôt was occupied by a motorised unit of the French Army. It was reported that what was left was in a severely worn condition only fit for scrap and that there had been much theft and pillaging. Boulogne fell into German hands on 24 May 1940. The Pas-de-Calais department became a zone of special control, administered by the "Oberkommando der Wehrmacht" in Brussels, Belgium. Along the coast was the "red zone". It was said that French law did not apply in this zone. Under the terms of the armistice, France was to hand over its railways to the Germans undamaged and was to work with the German authorities to restore them to serviceable condition.