American and Afghan forces were briefing each other at a forward operating base on March 11, 2013, about that day's mission when machine gun rounds suddenly rained down on them.
The group immediately looked to see where the shots were coming from. The lone airman in the group, then-Tech. Sgt. Delorean Sheridan, identified the source of the shots, which turned out to be coming from a truck in the base's motor pool.
"Initially, everyone starts to look to see what's going on," Sheridan, a combat controller, later told Stars and Stripes. "We're accustomed to shooting, so our first instinct is, 'OK, what is the person shooting at?' I turned and looked back and I saw this guy shooting at me, and the light bulbs hit: It's some guy trying to kill us."
The shooter was a new member of the Afghan National Police who had slipped unnoticed to the bed of the truck and taken control of its machine gun.
It was a so-called "green-on-blue attack" — when supposed allies attack friendly forces. Meanwhile, insurgents from outside the base joined what was clearly a coordinated attack, sending more rounds into the grouped-up men. Bullet fragments even struck Sheridan's body armor.
Sheridan decided that Afghan National Police officer or not, anyone who fired on him from within hand grenade range was conducting a near ambush and it was time to respond with force. He sprinted 25 feet to the truck and fired at his attacker up close and personal.
The airman hit the shooter two times with shots from his pistol and nine times with his M4, according to his award citation.
Once the on-base shooter was down, Sheridan ran back into the kill zone where the machine gun and AK fire from outside the base was still coming in. He grabbed the wounded and carried them to cover and medical aid.
As medics worked to save the wounded, Sheridan called in MEDEVAC flights for the 25 men hit in the fight — an airlift that required six helicopter flights. Twenty-three of them would survive the battle.
While the MEDEVACs were coming in and out, Sheridan assisted with carrying litters and called in strikes on the insurgent forces still attacking the base. The close air support broke up the enemy's attacks and killed four of the militants.
Sheridan was recognized for his valor with the Silver Star and a STEP promotion to master sergeant.