In this -- streaming video you can sit -- -- -- laptop -- TV for hours glued to what seems like an endless -- of fascinating. Documentaries -- to do so. Would likely mean coming across the late Tim had turned to -- he -- fearless filmmaker. And Nightline contributor. Who died tragically. But doing what he did best chasing danger tonight ABC's Bob Woodruff gets a look at the HBO documentary made to honor Tim Heather -- it's called. Which way is the front line from here. On April 20 2011. -- covering the civil war in Libya. Photojournalist Tim Hetherington was killed. Fatally wounded in a mortar attack that also took the life -- photographer Chris Tom gross and injured several other journalists. Weeks earlier Tim had been a world away attending the Academy Awards nominated along with fellow filmmaker and friend Sebastian younger. For the powerful Afghanistan war documentary which strap -- And. World war. And we wanted to bring the boy who was living rooms including senior citizens. And you know remind them -- didn't stay within. Now Tim's death and more importantly his life. The subject of younger his latest documentary called which way is the front line from here they might work as a photographer filmmaker I always looked dubious personal subjects also. Why did you decide to do this -- there. -- was a really really good friend of mine and I was just devastated by his death that a lot of questions it was kind of a mystery. What happened in the strata that ought to sort of like higher level he's -- that I want to make a film that. Would allow other people who never knew him. To be to be inspired by. Inspirational. He was capturing images of conflict first and Liberia's civil war and then all across the globe. For him it was not so much about what it looked like it was about how the people feel about each other. Missile weapons causation you know who received -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- would relate to his subjects as real people. And that allowed viewers to see gradual and -- America. Real people as diverse is a fisherman's Sri Lanka. Two American soldiers fighting from -- -- in Afghanistan. The 2007 Tim and Sebastien. Embedded for a total of ten months with American troops fighting in the extremely violent -- -- valley of Afghanistan. World it was a sense that we. -- now. Going to be -- and that was -- not a great feeling. Shooting for both Nightline in the film was stressful -- camera caught the Connecticut habit of combat. And its tragic outcome -- a member of the units that were with was killed. I sold distortion rule have been shock. And -- sore. It was just pandemonium. Tim was felt very very guilty about videotaping. A soldier. Who was killed and videotaping the reactions of his Brothers around them he really felt guilty about it. -- -- But -- documentary also shows how -- saw something else buried underneath the loud gunfire the violent attacks. -- the silent photos of the people. Sleeping. He said you know when the least interesting things about combat is combat. This stuff that's going on out here between the fire fights the emotions between the men. They connections in this within this group on missile Hilltop and that's really interest thing. And what she was able to see was their vulnerability. There was impressed by how much -- these guys are Tim saw their vulnerability why is -- able to look through that others cannot. That's a good question I don't know he just really kept his eyes open he was not interest in the obviously. -- -- sort of the obvious things. As a result of Tim's death in Libya Sebastian was haunted by the fact he could have been saved. If someone there with them had experience in first -- so Sebastian started risk. An organization with the sole aim of teaching freelance reporters -- to operate like army met. We are turning 24 people at a time. Sending them back out the front lines -- they're doing incredibly greater interest or they're not just crossing their fingers and hoping for the best. They realize that they have the skills and the equipment to deal with most combat medical emergencies -- -- we remember about ten. Tim lived a really big life. He was. Very very curious about the world insatiable curious and he was incredibly compassionate towards other people. And it could be a taxi driver in New York City or refugee. In Libya -- American soldier. He didn't make any distinction is at all he was just incredibly compassionate and humane about -- about this sort of the -- quiet dignity of the human struggle. And I. Have no desire to be kind of war firefights -- -- from wasn't wasn't. I have no move. Really I really care about the toll free I have no interest in photography can say. -- interest in reaching people and ideas and engaging them with Jews in the world -- For Nightline I'm Bob Woodruff in New York. A great journalists the documentary which way is the front line from here premieres April 18. On HBO.