>> reporter: the first shots were fired at the watch station just off the main entrance where caleb watson and private first class cameron walters were posted. it was the 21-year-old's very first day on watch duty. both men were unarmed. cameron died immediately. caleb was badly wounded and left for dead. >> i went into my supervisor's office, i hid under his desk. >> i was praying, "god help me." then i hear the glass break. and then i get shot. he fired. stopped. reloaded. kept firing. i thought i was going to lose my life. it was as if, you don't move, you die. >> reporter: johnson and two co-workers jumped out the window to escape. he had been shot seven times. ask he could still hear the gun firing. >> all units, active shooter at nas, building 633 on the main side, units responding, channel 3. >> reporter: at the watch station, caleb watson, badly wounded, dragged himself to the lobby, yelling at incoming sailors to leave, take cover. but alshamrani returned and shot him again. another unarmed american airman, 19-year-old mohammad hypen, fresh out of boot camp, heroically ran into th

. >> reporter: the first shots fired at the watch station where caleb watson and cameron walters were was praying, god help me. >> reporter: he fired seven rounds into johnson, but a keepsake from his mother would save his life. >> in my wallet there was a metal card my mom gave me before i went to boot camp and it had a message on it wishing me good luck and safe return. right here is the bullet hole. >> this was the card? >> this is the card that stopped the bullet. >> what did she say? >> i want you to stay safe and come home. >> she had no idea. >> she had no idea this was my armor. >> reporter: down the hall jessica pickett, a 20-year navy veteran, mother of four, was hiding beneath her desk. >> all i could think was how could somebody in uniform do this. why is it happening? >> reporter: he shot pickett nine times, two years later she lives with chronic pain and cannot understand how an al qaeda terrorist could infiltrate the ranks. >> it makes me angry. america has been betrayed. >> reporter: at the time the saudi kingdom condemned the attack and extended its condolences pledgi