life. they did hear some banging noises from beneath the debris yesterday. and they are holding out hope they might find some victims alive. the firefighter leading the rescue effort talked to cnn last night. >> so in this type of collapse, even though it is a pancake collapse, as the slabs of concrete slide and -- and move toward the ground, they do create voids, you know, as the rubble crushes and slabs of concrete land on top of it. there are, definitely, voids. so we are hopeful that we will find patients in those -- in those spaces. >> we're using canine assets from miami-dade fire rescue and florida task force one, as well as listening devices that we have as part of our cache of equipment. we, also, stop and hail callout. to in the rubble pile, listening for any sounds, tapping, voices, anything we might hear. so occasionally, we'll stop all of our operations. and just have everybody go silent, and listen. that, in conjunction with the dogs moving about their -- the