Which of the following events that resulted in tragic consequences for people, animals, and the environment did not occur after midnight, suggesting that they may have been caused or at least contributed to by operator fatigue?

a. The 1989 Exxon Valdez oil spill
b. The 1986 Chernobyl nuclear accident
c. The 1986 Space Shuttle Challenger disaster
d. The 1979 Three Mile Island disaster

Answer: C