LONDON--U. S. Army Flying Fortresses struck a terrific blow at the German submarine base at Lorient, on the coast of France today and American-built Mustang fighter planes made history by flying all the way to Germany to shoot up the Dortmund-Ems Canal area.

Vichy dispatches said 100 were killed and 450 wounded at Lerient in one of the most destructive Allied raids of the war on French territory.