Joe has a great example of what even a small detonation will do to steel plate.
PSI is sometimes a misleading measure.
Take air pressure. 14 PSI doesn’t sound like much but put a human sized door between 14 PSI and a vacuum and you have 21 tons of pressure.
That’s how the slight breeze on a small sail can produce over 10 tons of pressure, pulling along a boat on the water.
Or how a little bitty amount of unconfined Boomerite can blow the crap out of welded steel plate.