New York City Example: 4 seconds after detonation
An overpressure of at least 10 psi. extends out for 1 mile. Concrete and steel reinforced commercial buildings will be destroyed or severely damaged out to the edge of this ring. The few buildings that remain standing on the outside edge of this ring will have their interiors destroyed. Though the thermal pulse is intense enough to ignite most materials, the shock wave will likely extinguish most fires in this ring. Landmarks affected by the blast at this distance include the Chrysler Building, Rockerfeller Center, the United Nations, and four hospitals. All of these buildings will be totally destroyed or so severely damaged that they will be unusable and will have to be demolished in the clean-up.
Most people inside buildings will be killed by flying debris or die as the buildings collapse. Almost all those outside and not in the direct line of sight of the blast will receive lung and ear drum injuries to varying degrees. Those in the direct line of sight will be killed instantly by the thermal pulse. Fatalities are estimated at 300,000 with many of the remaining 100,000 receiving some form of non-fatal injury. Those people in this ring making use of New York's subway system will escape with few injuries, though they may be trapped for days by debris blocking entrances and exits.