They explode, as hospital fails badly (1-5)

I believe the answer is:

h-bombs

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'they' is the definition.
Both the answer and definition are plural nouns.
Maybe they are linked in a way I don't understand?

'explode as hospital fails badly' is the wordplay.
I cannot quite see how this works, but
'hospital' could be 'h' (abbreviation for hospital on maps) and 'h' is found within the answer.
'fails' could be 'bombs' ('bomb' can be a synonym of 'fail') and 'bombs' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in The Guardian.

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