See the original article here: U.S. Army to Spend $500 Million Training Soldiers to Fight Underground

The DOD will provide $572 million to train and equip 26 of its 31 active combat brigades to fight in large-scale subterranean areas—such as sewers or railway systems—that exist beneath dense urban areas around the world.

newsweek.com

SNN Editor: An older article. Nevertheless very relevant to what’s been going on.