A terrible fire at the end of the street involves repair (5)
I believe the answer is:
refit
'repair' is the definition.
(I've seen this before)
'a terrible fire at the end of the street' is the wordplay.
'a terrible' indicates anagramming the letters.
'at the end of' says to take the final letters.
The final letter of 'street' is 't'.
'fire' with letters rearranged gives 'refi'.
'refi'+'t'='REFIT'
'involves' is the link.
This may not be right. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for refit that I've seen before include "provision of new equipment" , "Update" , "Overhaul (ship)" , "Equip anew" , "Refurbishment (of ship)" .)