After the Bulls won their third straight title Michael had a change of heart (or possibly a mid-life crisis caused by the murder of his father in July) and on October 6, 1993 retired from the game of basketball. An act he would pull two more times (and counting).
It absolutely stunned the NBA as he was coming off an All-Star appearance, a scoring title, led the league in steals, made the All-Defensive Team, was First Team All-NBA, won a championship, and was Finals MVP. He was just 31 years old and seemingly at the top of his game. The modern day equivalent would be Kobe hanging it up...three years ago.
Jordan's intent was to play baseball which we'll cover in retro year: '94. Hint: it ended well for the NBA, not so much for the MLB.