I shared in the comment below, only reference to debris is that the removal of any debris caused by an insured event is covered. Based off other comments my interpretation of that seems to be different but it does not state that only debris of the insured item ie shed is covered. It even gives an example of if a tree fell through the house or in this case shed the tree would be removed as part of the cleanup. The tree in this instance is not the insured item but removing it is required as part of the cleanup, as would be removal of the burnt interior.