architect mona el hallak is fighting to preserve it.llak: this corner was called in 1976, "the door to hell." damascus road became the green line. the green line is what really divided beirut east and west. lemonis: the barakat building sat on the dividing line between a mainly muslim west beirut and a mainly christian east. upstairs, snipers were positioned behind sandbags targeting the street below. el hallak: and then you're here. and you're looking. and this is where you would have killed someone. you would have been the sniper. and you would have killed anyone who crosses in front of you. and today, this street -- lemonis: and their job was just to stand here... el hallak: and kill. lemonis: ...and you see somebody, old lady, little child, doesn't matter. el hallak: when the order comes -- the order on the walkie-talkie comes, shoot. lemonis: shoot. through a quirk in the building's design, the snipers couldn't be seen by anyone outside even when they were shooting. el hallak: you could shoot all the way down to the end of damascus