During the Vietnam War, one of the most dangerous jobs was that performed by a select few known as "tunnel rats".
These unsung heroes were American, Australian and New Zealand soldiers specially trained as combat engineers, who slithered through underground Viet Cong tunnels to perform dangerous covert search and destroy missions.
The tunnel rats cautiously sought out the armed mines to disarm them, praying to survive with their limbs intact. Most of the men were volunteers and tended to be short in stature, making it easier for them to maneuver through the cramped underground spaces.