In June 1940, via the Dunkirk evacuation, his son Alexandre Rosenberg had escaped to England. There he was commissioned as a Lieutenant into the Free French Forces. After being part of the D-Day Invasion, in August 1944 north of Paris a troop under the command of Lt. Rosenberg dynamited tracks north of Nazi train No. 40,044 and seized it, as it was attempting to transfer looted treasures to Germany. Upon his soldiers opening the train's boxcar doors, Alexandre viewed many plundered pieces of art that had once been displayed in the home of his father. The seizure saved about 400 pieces of his father's art from being lost, including many masterpieces. Alexandre was demobilized in 1946, and left immediately for his family in New York to join his father's business. The train's interception was the inspiration for the 1964 film "The Train", starring Burt Lancaster, Paul Scofield, Jeanne Moreau and Michel Simon.