Of course, it's perfectly possible that 'Metropolis' is only a name, and not the actual location, much as Arkham Asylum is located in Gotham but never referred to as 'Gotham Asylum'. At this point, I'm not sure whether Superman's hometown had been named yet - most of the early issues of Batman and Superman tend to fall back on New York as the de facto hometown for their heroes; note that the monster attack above takes place in 'lower Manhattan'.