Not many were damaged as badly as this house in the photo. KTTU has a good article and video on the damage to this house. I did a little research on this home to try to find out why it was so damaged while the houses near it were relatively unscathed.
This house is in Palmer on a particularly windy street. The Matanuska River Canyon comes down straight at this neighborhood and then makes a turn to the south right here. So the wind has been funneled directly at these houses. Still, this house was built in 1985 and has weathered many stronger winds over the years. It’s possible that a few upwind trees are missing, or some other physical change in the immediate environment changed to make this year the downfall of this roof.
One thing that I noticed while watching the video is that this roof was apparently skip sheathed. That is, instead of a complete decking of plywood under the metal roofing, a 1X4 or 1X6 was nailed horizontally to the trusses and the metal was attached directly to them. The 1X4s were stapled to the trusses and the staples looked like they didn’t hold well enough and pulled out. Once one of the 1X4s worked loose and the metal peeled up it was all over.
In the future I will always be nervous about skip sheathing in windy areas.