Transcript for Disarming Explosives in Afghanistan
For American troops serving in Afghanistan one killer has surpassed all other -- improvised explosive device. They've either taken the lives -- shattered the bodies of more than 8000 US service members in that war over the last decade and there are subject. Relentless scourge because there are so easy to make. What will know how and a couple ingredients that turn out to be disturbingly easy to buy here's ABC's -- Schiffer for our series. Nightline investigators. It. Down -- flooded road in Afghanistan nothing scares US troops more than -- I -- -- just blew up beneath his truck. Everyone. I eat these are the US is an enemy number one in Afghanistan. Others they've killed or wounded more than 8000 American troops and the numbers are getting worse. This close it gets to the source of all our problems. -- meet surgeons basically. He's an explosives ordnance detection technician better known as a member of the bomb squad. It's like -- game with the insurgents who gets to reverse. Who makes it -- -- President. -- to be a long night. Hopefully everybody expects -- -- that's clean team leader staff sergeant Terry scope. On nine elevenths he was a freshman since he joined the military after he graduated and deployed to eastern Afghanistan six months ago. We're really surprised me is being out of ideas -- and well over a hundred. Well over a -- over 200. 1 of those bombs killed staff Sargent Mike Garcia on the fourth of July. But it wasn't a random blast the -- bomb -- the bomb just for him use my first team leader -- -- here. And after Garcia died Schofield replaced. -- has that -- it. Sucks. -- learn what they did wrong what they taught you what they're doing right in stride -- job done but this is no ordinary -- -- intense. But Ehrlich every time you drag on the road here are buying everything from -- you roll over it get up. On this he'd seen a call comes in and -- -- buried in a road we set out in a convoy of armored trucks. At the scene Schofield walks to where the idea is there we aren't allowed to follow so we filmed it from inside the truck. Schofield finds a forty pound -- that when you're out here -- faith. This news stay away as far as possible to keep that distance the use of robots armed with the highly explosive C four to detonate the IET. The robot takes the risk to the men don't have to. Inside the truck clean you navigates the robot using the screen and a choice. And then after the -- dropped the -- four on top of the ID after everyone is ready. That bomb could have killed four soldiers -- in an armored vehicle. ED. A -- approximately four or five splattered everywhere roads -- After packing up they head home to the Afghan version of CSI. -- this might be the most important part of what we're there. Every bomb carries the signature of its creator so clean tries to find a fingerprint or -- piece of DNA goes into the system. It you know established do it -- -- -- -- -- And we can Trace back eighties and Traci VI CDs often leads them out of Afghanistan a lot of stuff comes but -- what's good stuff. And so my next destination -- start to look for the source. This country if the US -- -- received twenty billion American dollars since 9/11. But according to the US military as much as 75%. Of the material used in bombs in Afghanistan. Come from one place it is this is -- -- the largest fertilizer producer in Pakistan. Last year it beat 350000. Tons of something called calcium ammonium nitrate. And that's what this is a bag of calcium ammonium nitrate. From packed -- -- -- -- white palace and smell like anything and it's sold everywhere in August on its legal here used for farming and agriculture. If you take this and add fuel and added detonation device you can create -- -- -- Just like the -- -- in this propaganda video. The same -- we found for sale are often smuggled into Afghanistan with their legal. This summer the US army -- 5000 pounds of underneath -- fake floor in a truck. Pakistan's government says it's beginning to regulate the sale of calcium ammonium nitrate. But Pakistani -- say they aren't required to know and don't care who they felt. They did they have put -- god sakes it's not poison shopkeeper told us. Well actually can be much worse -- please. This man knows well and how much ammonium nitrate -- do you need. The creative you're from observable fifteen pounds is enough says -- Saudi Mohammed. He helped kill a female politician and a religious leader in Kandahar with ITT's brought from Pakistan I met him in jail in Kabul. But a lot -- -- -- what went up making explosives isn't that difficult he says we took the fertilizer connect detonator and a remote it's easy. It's even been easy in the US. Seventeen years ago Timothy McVeigh blew up the Oklahoma City federal building with ammonium nitrate congress -- -- legislation to track it. Until this year. The US asking Pakistan under regulated in months. Pat Garrett has sent a version of its calcium ammonium nitrate to the Pentagon -- -- can be easily tracked. But that's a long term solution. Scofield and -- and still have a lot of work to do. Because this is the sad fact no matter how many missions these men execute. The -- how many. -- flow of calcium ammonium nitrate is stopped. IUDs will continue to explode. And killed more and more US soldiers. For Nightline I'm mixture for an in -- -- Afghanistan.
This transcript has been automatically generated and may not be 100% accurate.