In “Blitz,” Steve McQueen’s powerful reconstruction of Germany’s World War II blitzkrieg attack on Britain, the most harrowing scene takes place underground. As London is attacked by Nazi planes, a bomb strikes a water main, which floods a subterranean subway station, trapping hundreds inside. The scene is based on a real-life incident that occurred in 1940, drowning dozens of citizens who were sheltering in the train tunnels. The “tube set” for “Blitz” was engineered to simulate a catastrophic