reports from the site of the dam at brumadinho, in south—east brazil. first, a long cloud of dust. then a nightmare vision of an unrelenting torrent of sludge. the waste from decades of mining racing towards hundreds of unsuspecting people down below. the catastrophe unfolded a week ago, but only now has this video come to light, adding to the sense of loss, and of outrage. and difficult for you. this red cross volunteer, henato silveira, leads me to the edge of the disaster zone. seis corpos. six bodies? he alone has found six bodies. any hope of reaching survivors in this endless sea of mud was quickly dashed. emergency workers are now scouting for any signs of bodies from the air, and they are picking their way over this horrific landscape. we spotted this search team with a sniffer dog in the distance.