Act of God
An event that directly and exclusively results from the occurrence of natural causes that could not have been prevented by the exercise of foresight or caution; an inevitable accident.
Courts have recognized various events as acts of God—tornadoes, earthquakes, death, extraordinarily high tides, violent winds, and floods. Many insurance policies for property damage exclude from their protection damage caused by acts of God.
Additional topics
Law Library - American Law and Legal InformationFree Legal Encyclopedia: "But for" Rule to Additional Instructions