This special instinct can help troops survive an ambush

In the spring of 1970, U.S. forces attempted to fracture an NVA supply line in the Vietnam jungle, as 79 soldiers from Charlie Company, 2nd Battalion, 8th Cavalry came under a vicious attack and became trapped in a heavily bunkered NVA fortification — unable to escape.

With nowhere to run, the troops began taking heavy casualties.

The hellish area was covered in thick towering trees which ruled out any possibility of dropping off extra supplies or evacuating the wounded. The only way to get to the ambushed men was from the ground.

Related: These are the most terrifying Vietnam War booby traps

If these ground troops were to lose this area to the enemy, the hope of an offensive victory would have died. The men at the point of attack managed to pull their wounded brothers out of harm's way and quickly render care. The American forces formed a secure perimeter with the men they had left.

"Human instinct tells you to stay on that ground don't move, return fire, don't move," Ken Woodard of Charlie Company explains during an interview. "You can get killed."

The men did just that, without being ordered.

They were then able to create a base of fire putting rounds down range — buying time.

Also Read: These were the terrifying dangers of being a 'Tunnel Rat' in Vietnam

Monitoring the radio 2.5 miles away was Alpha Troop who closely studied how Charlie Company was maneuvering and volunteered to go in as a quick reaction force.

Led by Capt. John B. Poindexter, the 11th Armored Cavalry Regiment (Alpha Troop) loaded up onto their Sherman tanks and armored personnel carriers and went in to help Charlie Company.

Not long after, the 11th ACR reached their brothers-in-arms in time and completed their rescue mission

Check out American Heroes Channel's video how these brave Americans reacted to being trapped by enemy fire.