An overpressure of at least 10 psi. extends out for 2.7 miles. Most concrete and steel reinforced structures will be destroyed or severely damaged out to the edge of this ring. All non-reinforced residential type structures will be leveled. Some buildings will be shielded by the hilly terrain of the city and suffer reduced damage. However, even these structures will likely have their interiors destroyed, if they remain standing. The thermal pulse will be attenuated by the fog to less than 2 cal/sq. cm. Significant structures affected in this ring include the Golden Gate and Bay Bridges, the Civic Center and the Presidio. It is very likely that both bridges will be completely destroyed by the blast.
