Total accident evacuated 40% of rural island (7)
I believe the answer is:
sumatra
'rural island' is the definition.
'sumatra' can be an answer for 'island' (Sumatra is an example). I am not sure about the 'rural' bit.
'total accident evacuated 40%' is the wordplay.
'total' becomes 'sum' (synonyms).
'evacuated' says to hollow out the word (remove centre letters) (internal letters are evacuated from the word).
'40%' becomes 'ra' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'accident' with its centre removed is 'at'.
'sum'+'at'+'ra'='SUMATRA'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for sumatra that I've seen before include "part of Indonesia" , "Large island of Indonesia" , "Some land" , "Second largest Indonesian island" , "Eastern island" .)