More than four years after zipping down a steel cable to provide medical care to a chopped-up platoon of soldiers, Master Sgt. Roger Sparks still labors to make sense of that day in November 2010 when four men died in his arms.

Jerry Giefer doesn’t recall much about what happened Dec. 30 at his office at the Army Corps of Engineers compound in Seoul. One moment he was working and the next, everything went black.

The view from the A-10 cockpits was troubling — low cloud cover and uncertain terrain below. The view from the ground was just plain grim.

The wounded U.S. servicemember was not far from Kandahar in Afghanistan. Three others were with him, but they could not get the injured man to safety because of an insurgent ambush. Nearby U.S. Army soldiers could not engage the enemy, and a close-air support coordinator on the ground was panicked and inexperienced.

U.S. Air Force Senior Airman Frank Troiano had two injured men with him, was taking fire from insurgents with a superior position and was trying to get out of a village in Afghanistan’s Tagab district.

No U.S. forces had reached the area in eight years of war in Afghanistan. Marine Corps Cpl. Ethan Nagel, an embedded trainer, along with his platoon of Afghan National Army troops, another Marine trainer and a small Special Forces team, were moving up the Uzbin Valley to meet with village elders.

The target was an expert bomb maker, suspected of killing numerous U.S. and NATO troops in western Afghanistan. As Staff Sgt. Andrew Seif and Sgt. Justin Hansen closed in on the enemy during a secret raid, the two Marines maneuvered to prevent the suspect’s escape.

The alarm sounds and the Coast Guard takes off, even when its rescue teams aren’t sure what lies ahead. Petty Officer 2nd Class Jonathan Kreske and three other crewmembers knew only that one man suffered a leg injury and another man might have been hurt when their MH-60T Jayhawk helicopter took off from San Diego around noon Jan. 18, 2013.

Jeff Hall was in his backyard, holding a 9mm pistol to his head trying to find the courage to pull the trigger. That was in 2008, after two deployments to Iraq that left him physically and mentally wounded.

Eight members of the 3-61 would die in battle nearby at Combat Outpost Keating two weeks later in one of the most costly engagements of the Afghanistan War. What Sean T. Ambriz was about to face was a prelude.