attack by government forces on the besieged city. one of the single most horrifying moments in syria occurred late last month. scores of people died in a town called douma as a result of government shelling. nearly three weeks later, we have our hands on video documenting this tragedy. she s live with us. take us back to what happened in douma on june 29th. reporter: the reason why it s taken three weeks to get our hands on that video is because the activists that wanted to shoot it were stuck there for well over a week and it was an ordeal to get the footage from damascus to us here in lebanon. we have to warn that the images are disturbing. the power is out in the streets. the three activists don t dare shine a light. there s a sniper lurking. gunfire in the distance forces them to pick up the pace. the activists are part of the oppositions media operation. they smuggled themselves into the damascus suburb last month and risked their lives to document this. a massacre s