New York City's video on how to survive a nuclear attack.

[Anomalocaris]

A hydrogen bomb is, of course, an apples to oranges comparison with a fission one, the former being two to three orders of magnitude more powerful, and, hence, more destructive.

Hydrogen bombs can be many orders or magnitude more powerful than pure fission weapons.    But Most modern nuclear weapons are not.   They are generally within roughly one order or magnitude of the Hiroshima bomb yield.

The yield of the bomb still does not invalidate the finding that sturdy buildings offer considerable protection against immediate physical effects of the nuclear blast.