The Tigers became the first team in major league history to blow a three-game lead with four games left.
Scott Kendrick has a list of the top 10 baseball collapses of all time; this will surely join them.
#1 is the 1964 Philadelphia Phillies, who "led by 6.5 games over the Cardinals and Reds with 12 to go in September, then lost 10 in a row" to finish behind the Cardinals, who had already fired their manager and general manager out of frustration at how their season was going.
Notably, neither the Yankees nor the Cardinals show up on Kendrick's list. Those are the two teams that have won the most World Series titles in the AL and NL.