[American in Israel]

As most Japanese buildings were wood and paper at that time, I wonder how modern stone buildings would hold up in comparison? Hope I do not find out...

[killjoy]

As most Japanese buildings were wood and paper at that time, I wonder how modern stone buildings would hold up in comparison? Hope I do not find out...

The buildings themselves will probably stand up quite well. The church at ground zero in Nagasaki was one of the few stone buildings in the city. After the bombing, its walls were still standing. IIRC, a large part of the damage from the two blasts over Japan were from fire afterwards, not from the actual explosions.

[DustyMoment]

As most Japanese buildings were wood and paper at that time,

Good mythology, but not true. At the Peace Park Museum, there are literally dozens of fragments of concrete that have images of people burned onto them.

[Husker24]

I would imagine it would just turn a stone building into a burnt out shell, if left standing at all.