Fight fire in storage facility (8)

I believe the answer is:
rucksack
'storage facility' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'fight fire' is the wordplay.
'fight' becomes 'ruck' (I've seen this before).
'fire' becomes 'sack' (dismiss someone from their job).
'ruck'+'sack'='RUCKSACK'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for rucksack that I've seen before include "large bag" , "traveller's bag" , "Hiker often carries one on back" , "A hiker's backpack carrier" , "Trekker's baggage" .)