Here's the IRS wording:
Casualty Losses - A casualty loss can result
from the damage, destruction, or loss of your property from any sudden,
unexpected, or unusual event such as a flood, hurricane, tornado,
fire, earthquake, or volcanic eruption. A casualty doesn't include
normal wear and tear or progressive deterioration.
https://www.irs.gov/taxtopics/tc515.html
Hard to imagine that a sinkhole wouldn't qualify..
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
