The tsunami that hit Japan's coast, washed away streets, brought down buildings and wiped away landmarks, essentially erasing any map of the region. This poses an immense challenge to relief teams who have to work immediately and systematically to save victims. Christoph Gorder, vice president of emergency response at Americares, explains the challenges relief organizations face when the entire grid of a city has literally been washed away. And Lasse Peterson, international director of Shelter Box, a disaster relief organization, has been to Sendai and Minamisenriku, two of the areas hit the worst by the tsunami. He says houses were literally "reduced to matchsticks."