Four seconds after detonation the shock wave will have an overpressure of 20 psi. at a distance of 1.4 miles from the site of the accident. Even the most heavily reinforced steel and concrete structures will be destroyed inside this circle. Fisherman’s Wharf, buildings on Alcatraz Island and a good portion of the north facing waterfront will be completely destroyed in the blast. Any ships inside this ring will be demolished. Roughly a minute later a wave over 50 feet high, created by the blast, will hit the shore.