Dig in a street that's about to crumble (12)
I believe the answer is:
disintegrate
'crumble' is the definition.
(I know that crumble is a more specific form of the action disintegrate)
'dig in a street that's about' is the wordplay.
'that's about' is an anagram indicator.
'dig'+'in'+'a'+'street'='diginastreet'
'diginastreet' anagrammed gives 'DISINTEGRATE'.
'to' is the link.
(Other definitions for disintegrate that I've seen before include "Fall apart - it isn't agreed (anag)" , "decay" , "Smash" , "Lose all cohesion" , "Decompose" .)