Recruits wear this M50 pro mask, which can protect soldiers from lethal chemicals. Rocco Candela: This is the M50 gas mask right here. This is the newer version. This is much lighter, better.

More than 40 million gas masks were issued ... It was also made lighter than normal masks so it was easier to wear. Contributed by John McFarline during the AHOW event at Enniskillen Library.

A sign hanging above the doors to the gas chamber reads, "Even the brave cry here." A dozen at a time, Marines are ushered into a small, dark, brick room. A thick haze of o-Chlorobenzylidene ...