Collapsed around part of church (4)
I believe the answer is:
apse
'part of church' is the definition.
(part of a church building)
'collapsed around' is the wordplay.
'around' indicates a hidden word.
'APSE' is hidden within 'collapsed'.
(Other definitions for apse that I've seen before include "room for an altar" , "Peas (anag) - found in church" , "where praetor sat" , "Church area" , "Recess at east end of church" .)