April 20, 2017:
(1) (1951) Dan Gavriliu performs the first surgical replacement of a human organ
(2) (2010) The Deepwater Horizon drilling rig explodes in the Gulf of Mexico, initiating an oil spill that would last 6 months
(3) (1745) French physician Phillippe Paul is born. He is known for writing a medical case that is now credited as the earliest recorded evidence of the existence of schizophrenia.