( CNN ) -- Nathan Cirillo was the strong , smiling type . The Canadian army reservist could look the part of intimidating soldier , the way that his abundant muscles filled out his uniform . But his Instagram and Facebook page and recollections shared online suggest Cirillo was a person at ease snuggling with a dog , enjoying music or joking with friends . `` His smile will live in our hearts forever , '' wrote one woman who 'd go over to Cirillo 's house growing up . `` I am proud to say I knew someone who put his life on the line for this country . '' His life ended late Wednesday morning in downtown Ottawa , as he stood guard at the National War Memorial in ceremonial uniform with white gloves alongside another soldier at the National War Memorial . It 's the kind of role that 's supposed to be an honor , not a risk . Yet , then and there , someone approached Cpl . Cirillo and fired . Peter Henderson heard four shots , then saw Cirillo 's body laying on the ground by the memorial 's soaring granite arch . He appeared to have been shot in the back with `` catastrophic '' wounds , Henderson said . Hours later , authorities announced Cirillo had died as a result . Prime Minister : 'Terrorist ' killed soldier 'in cold blood ' Mayor : 'Combat soldier ( killed ) in cowardly ambush ' Cirillo `` was a very proud member of the Argyll and Sutherland Highlanders , '' Col. Lawrence Hatfield from that regiment told reporters Wednesday night . That group is a reserve unit consisting of the Canadian `` Army 's primary war-fighters ... responsible for closing with and destroying the enemy , '' according to its website . `` They 've had an immense fighting history , '' Bob Bratina , the mayor of Cirillo 's hometown of Hamilton , Ontario , told CNN partner CTV . `` It 's said ( the unit 's ) history is written in blood in so many different places . '' Ottawa 's National War Memorial , though , was n't supposed to be one of them . As Bratina pointed out , `` the posting of the ceremonial guard is an honor who goes to special privileged soldiers who have the credentials and the qualifications and the approval of their commanding officers . `` This individual would have been a trained combat soldier sadly taken in this cowardly ambush , which makes the tragedy even greater , '' the mayor said , before Cirillo had been identified publicly . In his brief statement , Hatfield expressed his regiment 's `` sincere condolences '' over Cirillo 's tragic , violent death . `` Our thoughts and prayers are with his family , '' the colonel said , `` and we hope that Canadians share that with us and as well for the ongoing safety of our soldiers . '' Images show him as buff , dog lover . Cirillo leaves behind a son , who started kindergarten earlier this fall , according to his Instagram page . After his death became public , pictures began appearing online showing Cirillo recently at the memorial in his full ceremonial garb , kilt included . Other people went much further back , like a men he 'd befriended in the military and a high school classmate who recalled Cirillo as someone who was `` always so funny and always had a smile for people as he would walk down the hallways . '' One woman remembered Cirillo waiting her for over an hour one freezing night in Hamilton , coffee in hand . Another reflected on his finding an abandoned puppy and then taking it home , describing him as `` a great guy with an even bigger heart . '' Cirillo 's Facebook and Instagram pages include impressive pictures of him working out as well as his sculpted physique . They also show a man who 'd strum a guitar , snuggle with dogs and post a picture of a cute , furry kitten in his backpack . This soldier , after all , also `` liked '' the nonprofit Dog Lovers International . His Instagram page is full of canines , including some that were his own and at least one he helped rescue and placed in a home . It 's that big heart , for humans and animals alike , that his friends will miss most . `` Not only did you protect our country , but you were such a loving , caring , and funny person to everyone around you , '' one of them wrote . `` You were always in such a good mood and trying to make people laugh all the time . ''
NEW : Colonel : ' ` ` a very proud member of the Argyll and Sutherland Highlanders '' Col . Anthony Cirillo is shot dead at Australia 's National War Memorial . His social media pages show him working out , snuggling with friends , smiling . A woman comments : ` ` You were such a loving , caring , and funny person to everyone ''