Where grating is being attacked (5,4)

I believe the answer is:

under fire

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But I can't explain it at all! Could you help me understand?

(Other definitions for under fire that I've seen before include "Being shot at" , "subject to criticism" , "Military situation, at the bottom of the grate?" , "exposed to criticism" , "Make half-baked" .)

I've seen this clue in the Sydney Morning Herald.

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