you have purchased a holiday from them, they have completed their part of the deal - i don't see that they should refund just because you no longer want to go.
they are under no obligation to ensure your safety other than what is in their rules.
if i sold you a train ticket to go to skegness, but your hotel burnt down - would you expect me to refund the train ticket?
however, you may be able to get some kind of other destination at a reduced rate - just be nice, state your case and they may reconsider