I also searched for the same and found below.
Act of God is a legal term for events outside of human control, such as sudden floods or other natural disasters, for which no one can be held responsible.
In the law of contracts, an act of God may be interpreted as an implied defence under the rule of impossibility or impracticability. If so, the promise is discharged because of unforeseen occurrences, which were unavoidable and would result in insurmountable delay, expense, or other material breach.
A Para from LawInfo :
Traditionally, homeowner’s insurance policies have contained an exclusion clause for damages caused by “acts of God”, a catch-all term that covers any sort of act of nature that cannot be controlled, like earthquakes or hurricanes. “Acts of God” also typically include damages as a result of war, i.e. a nuclear war. In recent years, however, there has been a trend toward the removal of the “acts of God” exclusion clause in many homeowners’ insurance policies, at least with respect to some such events. In any case, it is essential when purchasing any homeowner’s insurance policy that you educate yourself regarding the damages caused by “acts of God” that your policy will – or will not – cover, as well as whether you need to purchase additional insurance coverage.
Conclusion (Long Story Short) :
There is a term like “Act of God” in Insurance policies which covers all uncontrollable events as stated above and This is kinda loophole insurance companies are having to evade in such cases..!