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

https://www.irs.gov/pub/irs-pdf/p547.pdf

Tax Law Provisions for Disaster Areas

https://www.irs.gov/individuals/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

https://www.irs.gov/forms-pubs/form-4684-casualties-and-thefts

Instructions for IRS Form 4684

https://www.irs.gov/instructions/i4684

IRS Form 4684

https://www.irs.gov/pub/irs-pdf/f4684.pdf

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.

https://www.irs.gov/newsroom/how-to-get-a-transcript-or-copy-of-a-prior-year-tax-return