Sebastian is the author of Tribe, along with War, Fire, Death in Belmont and The Perfect Storm. With Tim Hetherington, he co-directed Oscar-nominated documentary Restrepo, which won the 2010 Grand Jury Prize at the Sundance Film Festival, as well as four other films. Sebastian is also the executive director of Reporters Instructed In Saving Colleagues, a non-profit devoted to training freelance war reporters in first-responder frontline medicine.