Day 2

Day 2 began with breakfast at the hotel before we convened at a nearby parking lot to form the complete team and plan our method of attack for the day.

Morning Team Meeting

From L-R: William Doughtery, Rebecca MacDonald,  Dr. John van de Lindt, Dr. David Prevatt, Dr. Rakesh Gupta, Giraj Kandukuri, Dr. Andy Graettinger, Dr. Shiling Pei, Sam Hensen and Pouria Bahmani. Not shown are Chris Karstens and David Roueche.

Our objective for today was to get a complete profile of the damage that occurred in representative areas damaged along the tornado’s path through downtown Tuscaloosa. We were able to do that through each of the team members having cameras synced up to a GPS unit. As we took pictures, they were later linked up to GPS coordinates on a map in an effort to obtain as complete picture of the impacted area as possible.

Several key observations were noted today. First, large portion of the residential housing in the path of the tornado was low-income housing. These were typically small, one-story buildings of masonry or wood construction and sustained considerable amounts of damage if not total devastation.

Second, a key source of failure in quite a few homes was a failure of the gable end trusses due a lack of a tie-in between the gable end wall and truss. With the simple toe-nail connections typically used, there is very little strength in the connection and when subjected to large internal pressures, the truss and/or gable end wall has often failed.

Failures at Gable-End

Third, the quality of construction, both in newer and older homes was generally rather poor. Base plates not bolted to foundations, brick facade not tied to sheathing properly and sheathing not attached properly, amongst many others, were all commonly seen.

Lack of Adequate Base-Plate Connection Strength

Altogether approximately 7 different sites were visited today and notes and photos taken from each. With a clearer overall picture of the damages, we are prepared to come tomorrow and begin to collect data to form transects at multiple locations along the path of the tornado.