The Snohomish County Executive and building department is screwed...
All the reports coming out about the Army Corps of Engineers studies and reports predicting something like this, and they were still issuing building permits? There are going to be huge lawsuits over this, and I really can't say I blame people for being upset--If you're going to impose the huge fees and bureaucratic systems they have, and then they fail to prevent something like this from being as destructive as this is? What the hell is the point? The average person thinks "Well, if they permitted this, it's safe to build here...". Ain't always true, that...
I'm not even a geotechnical type, and I'd have taken one look at that hillside and said "Nope... Not living there...". Add in the fact that the trained guys were telling the authorities that there were issues, and you really start to wonder what the hell they were thinking. Supposedly, they were building right along during the same 2006 period the first slump happened. Absolutely nuts.
Not to mention how many other sites there are with similar issues all over the West side of the Cascades. Most of the Puget Sound area is just glacial moraine that the last Ice Age just piled up every which-way, and none of it is very stable under the wrong set of circumstances. If they ever have a major earthquake come along during the part of the year when that terrain is fully sodden with moisture, God knows where the casualty numbers will wind up. Some of that stuff is basically just very stable quicksand, just waiting for the right conditions to turn into soup for a few minutes. And, then immediately go solid. If you've ever seen the shaker-table films where they simulate what that kind of soil does during an earthquake, you'll be out looking for a chunk of bedrock to build your house on, believe me.