this is the story of a cnn team that got into syria s most dangerous city. to reach a handful of citizens risking their lives every day. to see firsthand, to bear witness, and to tell the world about the suffering, the grief, and the courage of homs. this is the account of 72 hours under fire. reporter: for more than a year, the regime of dictator bashar al assad have used brutal force to put down a popular uprising in syria. across the country, protesters demanded change, chanting down with the regime. this is another rocket in a civilian home. reporter: the city of homs became the beating heart of a growing uprising. but the syrian military sealed off one neighborhood as it tried to crush the revolt. the assad regime is shelling relentlessly these neighborhoods. there are snipers positioned in areas that are, you know, killing people as they try to leave their homes. this is a civilian neighborhood where people were living normal civilian lives being bombarded