In early June, Eric Rice, PE from our office, visited Joplin, MO to provide structural investigations for insurance claims related to the recent tornados damage. Eric worked with clients on the periphery of the tornado path, often within 1 - 2 blocks of the devastation swath of the tornado. Here are some observations and lessons learned:

- Eric saw utter devastation reported on the news. In the direct path of the tornado, nearly all objects were reduced to debris of a uniform size, almost as if it had been run through a food processor. In fact, people reported that the tornado sounded like a blender.

- The debris field extended vertically up to 15,000 feet - 3 miles in the air!

- Often, a main tree trunk remained, albeit stripped of its bark.

- Though pavement was slightly more cracked, it generally was not ripped up by the tornado. It is almost surreal to see everything destroyed on both sides of the road, yet the road itself is in good shape!

- Eric's investigations involved damage from directional high winds, meaning high winds coming from predominantly one or two directions. The tornado generally passed from west to east. Eric's projects were located on the south side of the damage path, and the wind damage came from the southeast and southwest high winds. Why?

- Surprisingly, tornados require a tremendous amount of air to sustain themselves. They draw this wind in from the ground, at the base of the tornado. The wind is not spinning, but directional, following the path of the tornado. This effect is clearly demonstrated in a video of another tornado from Springfield, MA. The tornado passed through the city of Springfield, then up the Connecticut River. If you watch the waves and river surface, you can clearly see how tornados suck in air. The video link: http://www.youtube.com/watch?v=W5plBdPBNj8

- Another surprising fact is that peripheral damage was not spread over a larger area. Eric was looking at high wind damage only a few blocks from the actual tornado path, yet some of the homes were substantially intact and sound. Much depends upon luck and chance.

- On the surface, it seems hopeless if you're facing such a huge tornado. However, in our research, we've learned that tornado Safe Rooms generally performed well, and that they saves a substantial number of people's lives.

- Here is a link to guidelines for construction of Safe Rooms: http://www.fema.gov/plan/prevent/saferoom/index.shtm