The most common and most likely answer to this crossword clue is the 10 letter word COLLAPSING
I've seen this crossword clue in The Guardian
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More clues leading to the result COLLAPSING
Buddy explains!

The straight part
We know that "Coming down" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case coming down = collapsing.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COLLAPSING mean?
COLLAPSING verb- To break apart and fall down suddenly; to cave in.
- To cease to function due to a sudden breakdown; to fail suddenly and completely.
- To fold compactly.
- To hide additional directory (folder) levels below the selected directory (folder) levels. When a folder contains no additional folders, a minus sign (-) appears next to the folder.
- For several batsmen to get out in quick succession
- To cause something to collapse.
- To pass out and fall to the floor or ground, as from exhaustion or other illness; to faint.