>> that's a rial good point.e people are putting their lives on the line for doing this type of work. it is not safe. it is difficult. it is dangerous. they do an incredible job under just the worst imaginable conditions. i can't even imagine how hard it would be for them to actually do that job. working in a slurry of mud and silt is difficult under the best of conditions. it's just hard to move, it's hard to get to stuff. they have a real difficult job on their hands, obviously. >> david, you mentioned a reaction that many of us have is we're shocked. how could something like this possibly happen. and the next question is, could this happen again? and what places are most vulnerable? >> well, you know, that's a question that geologists wrestle with all kinds of hazards, it's part of what we do. landslide hazards in the northwest are different than in different parts of the country. but all parts of the country, except very flat areas, have some risk of landslides. if you look up and down that particular valley,