Over, they gain momentum, but it's the momentum of the entire mass. it only takes five people pushing against one to break a rib, collapse a lung or smash a child's head. >> governments said there could be 8,000 people in the tangled mess on the bridge. they had to start at either end and untangle people, pull them out one by one. >> trying to free up vital room on the bridge, many decide to take their chances in the tunlai sap river. >> these young men and women who were willing to jump off of a bridge that they didn't know the depths to, and a lot of whom didn't even know how to swim, just t...