Most of the forts were integrated into the Maginot Line, if I'm not mistaken. However, as World War 2 wasn't like World War 1 in several ways, it's role was diminished significantly, as highlighted during the 1940 blitzkrieg. Indeed over my time researching, I've noticed that areas such as Ypres and Verdun were eventually captured by the Commonwealth and US respectively, but it generally doesn't go beyond that information wise,though it's not a stretch to say that they were captured with little to no opposition as after the rapid movement across France following both the Normandy breakout and the crossing of the Seine, the Wehrmacht was routed. However, although the Verdun front in particular was fairly quiet during the Second World War, the areas just east and south at the towns of St. Mihiel, Nancy, Commercy, and the fortress city of Metz were not. These areas were heavily fortified by the Germans and taken by Patton's Third Army, specifically the 80th Infantry Division in the cases of St. Mihiel and Commercy over the course of three months. Notably, a battle involving a major fort did occur during this time: the capture of Fort Driant, a linchpin in the defense of the city. It took 3 weeks to take the fort, with the Americans sustaining about 800 casualties.