Question. >> reporter: the debris field is full of a toxic sludge, a combination of human waste. chemicals from households, as well, has propane tanks, oil and gas making the search effort extreme extremely dangerous. every person, animal and is thing that comes out of here has to be decontaminated. workers are forced to wait for some areas to dry out before investigating. pumps have helped to clear some of the water where search dogs have picked up human scent. all this heavy equipment is helping to clear the debris off the road to provide more access for rescuers. but the debris is staying p...