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' indicates anagramming the letters.
'thus' with letters rearranged gives 'HUTS'.
'may be' acts as a link.
(Other definitions for huts that I've seen before include "Cabins" , "Shacks" , "Sheds" , "Wooden shelters" , "Temporary dwellings" .)