The slide, which occurred on Saturday morning, was triggered by heavy rainfall and reported to be about 25 m (80 feet) deep in some parts. In 2006 after a smaller landslide occurred on the north fork of the Stillaguamish River, millions of dollars were spent on regional mitigation measures. In 2010, a report commissioned by the county in order to be in compliance with federal regulations identified the hillside that collapsed Saturday outside of the community of Oso as particularly susceptible. Presentation courtesy of Dr. Walter Hays, Global Alliance for Disaster Reduction

2. MUDSLIDE IN
WASHINGTON STATE, USA
SATURDAY, MARCH 22, 2014

3. LOCATION MAP

4. LOCATION MAP

5. LOCATION MAP

6. LOCATION MAP

7. SNOHOMISH COUNTY,
WASHINGTON STATE

8. THIS SITE AND THE
MUDSLIDE WERE NOT
SURPRISES

9. PRIOR PREPAREDNESS
ACTIVITIES
• In 2006 after a smaller landslide
occurred on the north fork of
the Stillaguamish River,
millions of dollars were spent
on regional mitigation
measures.

10. PRIOR PREPAREDNESS
ACTIVITIES
• In 2010, a report commissioned
by the county in order to be in
compliance with federal
regulations identified the
hillside that collapsed Saturday
outside of the community of
Oso as particularly susceptible.

11. THE 2014 MUDSLIDE
• Officials described the
mudslide as "a big wall of mud
and debris” that blocked about
a mile of State Route 530 near
the town of Oso, about 55 miles
north of Seattle.

12. THE 2014 MUDSLIDE
• The slide, which occurred on
Saturday morning, was
triggered by heavy rainfall and
reported to be about 25 m (80
feet) deep in some parts.

13. WALL OF MUD MOVED
AFTER HEAVY RAINFALL

14. THE MUDSLIDE

15. THE MUDSLIDE

16. The 15 million cubic feet
mudslide destroyed about
50 homes

17. DESTROYED HOME

18. PREPARING FOR S AND R

19. SEARCH AND RESCUE
WAS HALTED FOR MOST
OF SATURDAY BECAUSE
THE SITE WAS UNSTABLE

20. FOUR-YEAR-OLD BOY
RESCUED ON SATURDAY

21. THE DILEMNA FOR SEARCH
AND RESCUE TEAMS
• The debris pile is about a square mile
(2 1/2 square kilometers) and 30 to 80
feet (9 to 25 meters) deep in places,
with a surface that includes quicksand-
like muck, rain-slickened mud, and ice.
• The terrain is difficult to navigate on
foot and very treacherous when heavy
equipment is brought in.

22. S AND R: SLOW, DANGEROUS
WORK WITH FEW SUCCESSES

23. S AND R: SLOW,
DANGEROUS WORK

24. HOPING FOR A FEW MORE
MIRACLE RESCUES

25. AN ALL OUT EFFORT
• A total of 156 workers were
taking part in search and
recovery efforts on Tuesday
and 50 National Guard
members were expected to join
later in the day..

26. THE SEARCH INTENSIFIES

27. Specialized teams and high-
tech equipment — including
technology to locate
cellphone pings under the
wreckage — were being
deployed on Tuesday

28. AN ALL OUT EFFORT
• With search and cadaver dogs
leading the way, rescuers used
small bulldozers and their bare
hands to push through sludge
strewn with splintered homes and
twisted cars to find 10 more bodies
in the debris of the mudslide.

29. SLOW DANGEROUS WORK

30. --- AS CONTINUING RAINFALL
INCREASED THE RISK TO THE
SEARCH AND RESCUE TEAMS
FROM POSSIBLE FLASH
FLOODS AND ADDITIONAL
MUDSLIDES

31. THE DILEMNA FOR SEARCH
AND RESCUE TEAMS
• To make matters worse, the debris
pile includes other hazards such
as fallen trees, propane and septic
tanks, twisted vehicles, and
countless pieces of shattered
homes

32. SLOW DANGEROUS WORK

33. Snohomish County Fire Chief
Travis Hots hailed the rescue
crews Thursday as “unsung
heroes,” noting their tireless
efforts to continue searching
for bodies.

34. Due to the dangerous
environment, as bodies are being
discovered underneath the rubble,
they are being flown out together
in groups each afternoon instead
of one at a time in helicopters.

35. Some survivors began to
grow impatient Wednesday
when they weren't allowed
to return to the sites of their
homes to search for their
valuables and memorabilia..

36. 176 MISSING
14 DEAD
AS OF TUESDAY, MARCH
25

37. AT LEAST 100 MISSING
24 DEAD
AS OF WEDNESDAY,
MARCH 26

38. AT LEAST 90 MISSING AND
25 DEAD, BUT THE DEATH
TOLL IS NOW EXPECTED TO
INCREASE DRAMATICALLY
AS OF THURSDAY, MARCH
27

39. AS TIME PASSES, IT IS
BECOMING PAINFULLY
CLEAR THAT SOME
BODIES WILL NEVER BE
RECOVERED