When U.S. Marine Lance Cpl. Derek Goins deployed to the most dangerous place in Afghanistan five months ago, he mentally prepared for the risk of getting shot by the Taliban or stepping on bombs buried throughout this southern river valley.
But he wasn't ready for what happened to his two best friends, who were shot to death inside a patrol base by an Afghan army soldier who escaped into the arms of the Taliban.
"I grew up with those guys in the Marine Corps and shared a lot of laughs and tears with them," said Goins, 23, from Trumbull, Texas. "We expected to come here and fight and not just get murdered, and that's what it was."
The Marines who arrived in Sangin district of Helmand province in October have seen the kind of tragedy and combat stress that few can imagine _ more than 30 deaths and 175 wounded, with scores losing arms and legs when they stepped on bombs.
The 3rd Battalion, 5th Marine Regiment and smaller Marine units attached to it are fighting to regain this key insurgent stronghold in one of the country's bloodiest regions.
At least 288 NATO service members were killed in Helmand province in 2010. Last year was the deadliest of the nine-year Afghan war for the international forces, with 701 killed.
Many of the Marines in Sangin say they are coping by blocking out the horrors they have seen. Psychiatrists say that behavior is normal during combat, but it could trigger post-traumatic stress disorder when the Marines go home next month.
"It's a day-by-day thing and you don't know if you're going to be the guy to get hit the next day, so you just keep on pushing," said Goins, who like most of the Marines in Sangin is on his first combat deployment.
Lance Cpl. James Fischer, whose platoon lost a Marine to Taliban gunfire the first time they patrolled outside their base, said he has become numb to even the most gruesome scenes.
"Afterward, you just don't get that shock anymore," said Fischer, 20, from Glendora, California. "You'll have to deal with it at some point, but right now the most important thing is keeping everyone around you alive."
Cmdr. Charlie Benson, a Navy psychiatrist who has visited the Marines in Sangin nearly a dozen times, said he has not seen an abnormally high rate of mental health issues in the battalion _ although it's too early to tell who will have problems when they go home.
Benson, 46, from Marcelus, New York, believes the Marines are coping relatively well with the combat in Sangin because they have good leadership and feel they are making progress. Sangin is a major narcotics hub that funds the insurgents and a gateway to stream fighters into Kandahar, the Taliban's spiritual heartland.
The Marines have stepped up their efforts to deal with combat stress in recent years by deploying additional mental health professionals with the troops. They also have trained medical corpsmen, chaplains and Marines to recognize when troops are having trouble coping.
"There is a lot of stress, and it's not just combat," said Sgt. Adam Keliipaakaua, a 26-year-old Marine from Newport News, Virginia, who is on his fourth combat deployment. "It's from back home, too, with people's parents getting divorced, people's wives cheating on them or leaving them."
Keliipaakaua said he tries to prepare his Marines for the nightmares and irritability they may face when they return home and have to deal their emotions.
"For me, I'm pretty much emotionally cold. My wife tells me that all the time," said Keliipaakaua, who suffers from nightmares of a Marine dying in his arms.
An average of 15 to 20 percent of troops who have traumatic experiences during combat often suffer post-traumatic stress disorder, or PTSD, when they return home, Benson said. The condition arises when troops continue to try to suppress emotions with drugs, alcohol or by avoiding situations that trigger painful memories.
"If you're having issues six months after the event, then that would be a good indication," Benson said. "One of the things that Marines hate is the feeling that if they had only done X, Y or Z, this guy would still be alive."
Psychiatrists often treat PTSD by having troops repeatedly tell the story that haunts them, forcing them to face their emotions and pushing them to see that often there was nothing they could have done to save their buddy, Benson said.
Sgt. Matt Lewoczko, a Marine in Sangin on his fourth combat deployment, said everyone deals with the horrors of war differently when they return home.
"Some guys are going to go back and it will be good to have their family, some will crawl into a bottle for a week, month or couple months and then will crawl out and be fine," said Lewoczko, 27, from Houston, Texas. "Unfortunately, some guys don't get over it."