The insurgent sniper hit him first. The Casper, Wyo., native was kneeling on the roof of the one-story outpost, looking for targets.

He was reaching back to his left for his rifle when the sniper’s round slammed into his helmet.

The impact knocked him onto his back.

“I’m hit,” he yelled to his buddy, Lance Cpl. Scott Gabrian, a 21-year-old from St. Louis.

Lance Cpl. Gabrian belly-crawled along the rooftop to his friend’s side. He patted Lance Cpl. Koenig’s body, looking for wounds.

Then he noticed that the plate that usually secures night-vision goggles to the front of Lance Cpl. Koenig’s helmet was missing. In its place was a thumb-deep dent in the hard Kevlar shell.

Lance Cpl. Gabrian slid his hands under his friend’s helmet, looking for an entry wound. “You’re not bleeding,” he assured Lance Cpl. Koenig. “You’re going to be OK.”