The devastating event changed his life forever. He twice attempted suicide and psychological problems broke up his relationship and left him homeless.
Kevin is not this 36-year-old Iraq war veteran's real name. He wants to conceal his identity to protect his children.
His is a harrowing story: diagnosed with post-traumatic stress disorder (PTSD), Kevin believes he would be dead if it had not been for the intervention of the Scottish Veterans' Residences charity, which provides rooms for homeless veterans in Edinburgh and Tayside.
Originally from Glasgow, Kevin joined the Black Watch, Scotland's best-known regiment, in 1996. He served for 11 years and was posted on gruelling operational tours to Kosovo in 2001, and was one of the first 300 troops to go to Basra at the start of the Iraq war two years later.
As a private, whose duties included driving, he was based at the Basra palace of the then Iraqi president Saddam Hussein.
"It was horrendous,'' he told the Sunday Herald. ''I had lost one of my good friends out there ... in a war that wasn't ours. Things that I was saw there were indescribable. Just bodies everywhere.
"The first three weeks was close combat with what I would say were terrorists. But in the end they were only doing what we would do, defend your country.
"Some of the things we did I am still not comfortable with speaking about ... picking up body parts and things."
Two years before he left the armed forces, Kevin's marriage broke up. He now admits that PTSD had made him more aggressive and controlling at home.
"I walk by a butcher's and it brings back the smells of being in Iraq ... the smell of dead flesh. I could be in the street and see something happening and it reminds me of something that happened there and it gets me on edge.
"When I was staying in a block of flats, people were pulling the security door; that would send a bang and that would sound to me like an artillery shell. So I put a camera outside my front door, and I had a bat at the front door. I was frightened in my own house at times.
"There are times I could be walking down the road and if I hear footsteps behind me, I stop and put my back against the wall.
"I lost my wife and three kids through me being controlling; asking where they were, what they were doing, who they were with."
Kevin left the Army at the insistence of a partner before he was due to serve in Afghanistan. But his difficult behaviour took its toll on another relationship after he settled in Wester Hailes, Edinburgh.
After being persuaded to seek help, he was diagnosed with PTSD two years ago after consulting with veterans' mental health charity Combat Stress.
"It wasn't me that was noticing my behaviour, it was friends and family who thought I was getting OTT with things. I was just saying I was fine.
"I initially took the help, but being the person I am, I was stubborn and said there was nothing wrong with me.
"I didn't want to continue with it. But then I was put on anti-depressants and that seemed to suppress things even more."
But in September his partner said that enough was enough, and for the sake of her three children from another relationship he needed to go and seek help.
With nowhere to go, Kevin went to Veterans First Point in Edinburgh, a one-stop shop for servicemen run under the clinical direction of NHS Lothian. But when he got there he was told the doors did not open until 1pm. He had arrived at 9am. "I said I was struggling. I was diagnosed with PTSD and life was hard and I was still turned away."
Luckily he had a friend's sofa to sleep on and after registering as homeless he was advised to speak to SVR, who found him a room in their 82-room Whitefoord House sheltered housing complex in Edinburgh. He has also received psychological counselling for the past two months.
"When I joined the army I thought, travel the world, there are no conflicts going on, I will be able to see this and that. But then I did get involved in a conflict - and it was hard to bear.
"My head has now turned full circle. I am now getting the treatment on a daily and weekly basis. I am getting a lot of things out, I am learning to spot the trigger points and how to deal with the anger."
But he says not enough was done through official channels to support him after he left the forces.
"Nothing was offered to me. I had depression on my records. They should have dug deeper into that. So I feel they failed in a duty of care.
"When you leave an operational theatre, you are asked, 'Is there anything you have seen or done that is going to affect you?' But when you are standing with 20 and 30 of your mates behind you, you aren't going to say 'Yes', because it makes you look weak.
"There should be more done. I feel people should be taken away and given a bit of respite before they come home to their family."