Tunnels of Vietnam.

Catching Killers (2021)

Here is the heroic story of a intrepid band of infantry soldiers, the "Tunnel Rats", charged with a daring mission–to search for, find, and destroy a secret subterranean network of enemy tunnels in Vietnam. Armed with only a flashlight, valor, and a .45, they faced a determined foe and overcame lethal odds, uncovering secret enemy arms and intelligence caches. Tragically, many of these volunteers died and others were seriously wounded on this terrifying suicide mission.