"The tests demonstrated that the below ground shelter door assembly was capable of resisting the missle impacts, per the guidelines of FEMA 320, and is therefore suitable for use as tornado shelters. The 15 lb. 2X4 missle propelled at 100 mph is required by FEMA 320 and relates to a missle propelled by a 250 mph ground speed tornado." The report further states that "The concrete portion of the Pyles shelter was 5 inch thick concrete reinforced with #4 rebar at 12 inches on center with 6x6x6x6 WWF mesh. The concrete design has been successfully tested many times and was not required to be retested. Note* FEMA does not endorse shelters of any kind. Shelter guidelines and specifications are established by the National Storm Shelter Association.