San Francisco was also attacked by a giant monster (courtesy of the late Ray Harryhausen) in 1955's It Came From Beneath the Sea
, just a year after the original Godzilla
. In fact, the giant octopus in that film was irradiated and driven from its normal feeding grounds by the exact same Marshall Islands nuclear tests that drove Godzilla from his (and that inspired the making of the film
in the first place).
I wonder if the writers chose San Francisco as some type of homage to one of the inpiration for Godzilla?