Result of implosion badly ruins hotel (6)
I believe the answer is:
inrush
'result of implosion' is the definition.
(an implosion might cause an inrush or flood)
'badly ruins hotel' is the wordplay.
'badly' indicates an anagram.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'ruins' anagrammed gives 'inrus'.
'inrus'+'h'='INRUSH'
(Other definitions for inrush that I've seen before include "Internal thrust" , "gaining sudden entry" , "An inward dash" , "Crowd invasion" , "Inflow" .)