Authorities: 108 People Unaccounted For In Deadly Mudslide

CBS Seattle ^ | March 24, 2014 11:58 AM | Unattributed - AP

[Mariner]

ARLINGTON, Wash. (AP) — The search for survivors of a deadly Washington state mudslide grew Monday to include 108 names of people who were reported missing or were unaccounted for, but authorities cautioned the figure likely would decline dramatically.

Still, the size of the list raised concerns the death toll would rise far above the eight people who have been confirmed dead after the 1-square-mile slide Saturday swept through part of a former fishing village about 55 miles northeast of Seattle. Several people also were critically injured. About 30 homes were destroyed, and the debris blocked a 1-mile stretch of state highway.

“The situation is very grim,” Snohomish County Fire District 21 Chief Travis Hots said, stressing that authorities are still in rescue mode and are holding out hope. But he noted: “We have not found anyone alive on this pile since Saturday.”

[Mariner]

Much of Western Washington is little more than glacier trailings...more than 50% rocks from the size of a golf ball to the size of a house. Filled in with sand and silt.

It gets very unstable when soaked.

Combine a bunch of rain like they've had this winter with a good-sized earthquake and it would be catastrophic. Much of the land mass would become soup.

[cuban leaf]

I lived in the Seattle area for 45 years and have ridden my bicycle through the area covered by that slide. I moved to Central KY in 2011. We own two fingers of a plateau about 80 feet over the valley below. My wife was asking about slides here. I’ve worked the dirt in both areas. here, if you dig down a few feet you get clay and limestone. It’s basically a big rock under us. Completely different.

It would have to be. We get torrential rains here on a regular basis (anything that can slide, has slid). That’s why I spent all day Saturday with my tractor re-grading the steep hill of our driveway that brings you up from the valley. It’s made of the dirt and when leaves clogged my ditch, it re-directed those torrential rain fed waters right down the middle of my driveway, creating an 18” deep and 12” wide grand canyon meandering right down the middle of it.

But when I dug out my ditch, I eventually hit the clay. It’s not going anywhere in a hurry.

[bert]

The graded bank tends to assume it’s angle of repose.

[lucky american]

Prayers up for the survivors and their families.

[driftdiver]

Hard to believe this happened in the US.

[cuban leaf]

Yeah. It hints at why valleys are deeper and sides more sheer on Mars.

[Red Badger]

A couple of dump truck loads of chert rocks would likely diminish that problem......................

[cuban leaf]

We actually had it professionally graded and put a three inch layer of “dense pack” down. But that was a little over 3 years ago. I’m going to complete the crown in it tonight and throw another load of dense pack down. It should hold us over at least another three years, partly because I’ve done a better job of re-directing the water flow this time.

BTW, concrete or asphalt is a no-no - it becomes a skating rink in freezing weather. Gravel gives good traction except with thick snow and ice, which we very rarely get.

[cuban leaf]

Hard to believe this happened in the US.

---

These things are becoming more and more common in western Washington state. I can think of at least three like this that happened in the last decade or so. This one just happened to happen in a place that affected more people (kinda like hurricane Sandy).

[Mariner]

And it’s nothing compared to what would happen if Mt Rainier just burped, much less actually erupted.

[Red Badger]

There are two problems to solve:

1. Break up the power of the flow of water.

2. Make it go somewhere where it won’t be a problem.

Your situation sounds exactly like where my daughter and her family live: On the down side of a steep hill that is not county maintained. Every rain they get washouts...................

[Red Badger]

Another ‘solution’ is to plant some vegetation that has deep roots to keep the soil in place................

[tcrlaf]

Meanwhile, CNN is still “BREAKING NEWS!” with nothing new to report about MH370.

I guess that’s easier and cheaper than actual “Reporting”.

[CincyRichieRich]

Good grief! How do you go from 3 dead to 8 to 108 missing and miss that info? Do the news orgs not even care about those NOT living in a city?

[RitchieAprile]

if Rainier’s snow cover melts, Tacoma would be swept away by the Puyallup and the Nisqually valley would become a canyon.

[cuban leaf]

In my case thre is a ditch, but the road has a hump in the halfway point where water can wash over the dense pack before it gets too fast and strong.

But over time the ditch on the hill side filled in with too much leaf debris and successfully blocked the overwash water causing it to veer right into the center of our road. The rain was torrential and even the dense pack could not withstand it.

I've significantly deepened the ditch and will deepen it further, eliminating the halfway point wash off but also fill it with those rocks that are approximately 7" diameter that everyone uses around here for ditches. That should make the fix permanent with minor necessary maintenance. BTW, Here is the hill (in the background). You only see the bottom but the hill (with the tip of the house showing) gives you an idea of how high it goes. And all of that climb is on the front of the hill.

Before we bought it (note the for sale sigh behind our rental car)

From the top (shortly after we purchased it and different rental car):

Notice that in both of those pictures it is just indigenous "gravel and rather bumpy. After we graded it, laid down the dense pack, and I trimmed those trees, it was actually very nice. And when we get the dense pack in, it will be again.

[hoagy62]

Yep. The lahar that would occur if the western face of Rainier let go would take out many small towns and go all the way to Puget Sound, possibly even taking out the Puyallup River Bridge. That'd completely cut off north-south access on I-5 for Seattle. Depending on how wide that collapse was, it could even possibly take out more towns along the Nisqually and possibly destroy the I-5 bridge over that river as well.

Scary thought all the way around

[hoagy62]

The Tideflats in Tacoma, not to mention Fife, would certainly be ruined, but most of Tacoma would survive being that most of it is WAY above the Puyallup River valley.

[RitchieAprile]

That area is pretty isolated, despite its proximity to Seattle. There aren’t a lot of ways to get heavy equipment in there to uncover these sites.

[Red Badger]

That looks amazingly similar to my daughter’s place, only less steep. Their road is at about a 40 degree angle.

Their problem is sand. The water just washes it away by the ton.........................