Loss by fire of cwip asset

Since loss is incurred, you need to transfer the amount of loss in the books. I'd suggest you to transfer it to p&l appropriation account as I believe it to be capital loss. it's a loss of abnormal nature. Also, the cwip was incurred to avail enduring benefit hence was a capital expenditure. Therefore I consider the loss to be of capital nature. Further I believe the expense is not an allowable expense for taxation purpose.

It is a loss of capital nature and should not be transferred to p&l a/c . Being a loss of capital in nature , it will not be allowed for taxation purposes also.