New York City Example: 6 seconds after detonation
In the next two seconds the shock wave moves out another half mile, extending the destruction out to a 1.5 mile radius. The overpressure has dropped to 5 psi. at the outer edge of this ring, which covers an area of 4 square miles. Reinforced structures are heavily damaged and unreinforced residential type structures of brick and wood are destroyed. Affected structures include Carnegie Hall, the Lincoln Center and the Queensboro Bridge. All the named structures are near the outside edge of this ring. All windows in these structures will be shattered and many interior walls will collapse.
This ring contains 500,000 people during the day. About 190,000 will be killed inside buildings by flying debris. This is roughly half of the assumed indoor population. The other 190,000 will suffer varying degrees of injuries. Most of those outside and not in the direct line of sight of the explosion will escape direct injury from the blast, but may be injured by flying objects. The thermal pulse is still sufficiently intense (40 cal/sq.cm.) to kill anyone in the direct line of sight; approximately 30,000. Those people fortunate enough to be under ground will escape with no injuries. The total number of injured will be approximately 220,000, leaving roughly 60,000 uninjured.
This region contains the most severe fire hazard, since fire ignition and spread are more likely in partly damaged buildings than in completely flattened areas. Perhaps 5% of the building would be initially ignited, with fire spread to adjoining buildings highly likely. Fires will continue to spread for 24 hours at least, ultimately destroying about half the buildings.