attempt to keep the river from further cutting the toe out of the landslide. the ancient landslide that was a piece of that re-activated was immense. the ability to engineer one's way out of the potential hazard there is probably just not available, not feasible. so efforts were made to try to prevent the river from further exacerbating a naturally very unstable slope. that slope had failed many times since the 1940s, as i understand it, every decade or two. unfortunately, the slide that happened this time was bigger, involved more hill slope, was more destructive, went farther across the liver, obliterated the flood plain. that was bigger than the slides that happened there before. if you look on the laser data, there's evidence of larger slides in the path. this occurrence is an example of how someday geologists warn may happen, can come to be today.