Fire loss of sold good by transporter.

You have to treat it as separate supply for gst. However if you adjusting it with freight charges also. 

Then risk and rewards is not passed, that means you are still the owner of goods

you have to use consignment accounting where sales cannot be recorded. 

Record consignment loss initially

Finally, record insurance claim of recovered amount 

but if you already made a sale on a Second thought, sry about that, record loss and record claim as credit.

When goods are destroyed by transit, then the "Loss by transit A/c" is debited and "Purchases A/c" is credited. The goods destroyed by transit is considered to be loss for the business and is classified as a nominal account. Therefore, according to the rule of nominal account, all the expenses and losses are to be debited.

I don't think purchases should be credited because the closing inventory itself is netted with purchases in COS. Here is a scenario 1 where the normal balance is 7300 when everything else is the same. 

 After the loss: Scenario 2

Finally after the claim: Scenario 3

The above compensated the loss and brought the balance back to normal. When it comes to sales return, bank balance is reduced.