beginning of the end vs death knell

beginning of the end

noun
  • The point when something starts to end or become worse. 

death knell

noun
  • A sign or omen foretelling the death or destruction of something. 

  • The tolling of a bell announcing death. 

How often have the words beginning of the end and death knell occurred in a corpus of books? (source: Google Ngram Viewer )