This is the fourth in a series of NIST Technical Notes (TN) on propagation and detection of radio signals in large building structures (apartment complex, hotel, office building, sports stadium, shopping mall, etc.). The first, second, and third NIST Tech Notes (TN 1540, TN 1541, and TN 1542) described experiments for radio propagation in a structure before, during, and after implosion. The data in these reports give first responders and system designers a better understanding of what to expect from the radio-propagation environment in disaster situations. The goal of this work is to create a large, public-domain data set describing the attenuation of radio signals in various building types in the public safety and cellular telephone bands.