Shelters may be thus wrecked (4)
I believe the answer is:
huts
'shelters' is the definition.
(hut is a kind of shelter)
'thus wrecked' is the wordplay.
'wrecked' is an anagram indicator.
'thus' is an anagram of 'HUTS'.
'may be' is the link.
(Other definitions for huts that I've seen before include "Cabins" , "Shacks" , "Sheds" , "Wooden shelters" , "Temporary dwellings" .)