earthquake vs freak accident

earthquake

noun
  • A shaking of the ground, caused by volcanic activity or movement around geologic faults. 

  • Such a quake specifically occurring on the planet Earth, as opposed to other celestial bodies. 

verb
  • To undergo an earthquake. 

freak accident

noun
  • An incident, especially one that is harmful, occurring under highly unusual and unlikely circumstances. 

How often have the words earthquake and freak accident occurred in a corpus of books? (source: Google Ngram Viewer )