These first three websites provide detailed information about the IRS Casualty Loss program for disaster relief.
Disaster assistance and emergency relief program for individuals
https://www.disasterassistance.gov/get-assistance/forms-of-assistance/4500
Casualties, Disasters, and Thefts
Tax Law Provisions for Disaster Areas
The following information refers to the IRS form 4684, used to report Casualty Loss claims. Your tax preparer will most likely be familiar with form 4684.
about IRS Form 4684
Instructions for IRS Form 4684
IRS Form 4684
If you have lost your copy of your prior year’s tax return, and your tax preparer does not have a copy, here’s how to get a copy from the IRS.