Colorado had a massive landslide this weekend. From first-peek at photos of the location and the initial dimension estimates, this is a catastrophic-scale landslide where over a million cubic meters of soft sediments flowed down the valley.
Source area of the landslide. Image credit: Pablo Spencer
Three men are currently reported missing. All other details are extremely sparse, and the dimension estimates have changed substantially between the two main reports. Apparently an aerial survey was conducted this morning, so I'm going to wait on those photos getting released before trying to determine the mechanics of what happened.
Really large landslides, those over a million cubic meters of volume, are strange. They flow out farther than we think they should, and our theories as to why that happens are unsatisfying.