sergeant jimmy regan, a former duke player, was killed in combat in iraq.nto words with his jersey and what his life meant to us. >> reporter: regan's death changed carroll's life. >> the day he died i made up my mind i wanted to follow this his footsteps. >> concerned? >> very concerned. >> in 2007 erin carroll was his college girlfriend. they got married in 2010. >> i tried to persuade him not to do it but i tried to make him aware as he already was of the danger of it but it was something he felt like he was born to do and so who was i to stand in the way. >> army sergeant carroll eventually joined regan's former platoon. he spent four years and spent four deployments in iraq and afghanistan, but here's what's really surprising. >> you never met jimmy regan. >> no, did not. >> what about the way he lived and died has meant so much to you? >> i really saw him as more of a trailblazer trailblazer. it's just that you have to kind of follow your heart and do something that is important to you. >> reporter: two years ago carroll returned to duke on the g.i. b