act of God
US /ˌækt əv ˈɡɑːd/
UK /ˌækt əv ˈɡɑːd/

1.
an instance of uncontrollable natural forces in operation (often used in insurance contracts)
:
•
The damage to the house was caused by an act of God, so the insurance company covered it.
•
The contract includes a clause for an act of God, excusing performance in such events.