topic. >> this is an issue because when a bridge collapses and there are, as you said, not just water underneath, but there are people and businesses, the rescue is complicated by the fact that there's still a bridge span up there that we don't know why the first one fell in the first place. this is uniquely difficult and dangerous because it's not like it's just aftermath and you're trying to find survivors. >> that's right. i mean, you're seeing these images, snarled rebar, lots of big chunks of concrete. this is tons of infrastructure that fell on to the heads of the people working underneath. these rescue workers, they're going through some death defying, daring stuff to get these guys out. we're seeing images of rescue workers trying to extract people, trying to take victims in rubble in stretchers attached to cables that are suspended from cranes. firefighterses climbing over these jagged pieces of concrete. so in many ways i think the rescue looks almost as terrifying as the bridge collapse itself.