Indianapolis turned 150 years old in 1971.
The motto for that year was "We celebrate our city," and there was even a special commemorative coin to prove it.
The pit badges for the 55th Indianapolis 500 marked the occasion as well.
And for the first time, management allowed women in the pits on a regular basis.
The track brought back 1925 500 champ Pete DePaolo to sing "Back Home Again in Indiana." and everything appeared to be on track for a great start and then, disaster.
The 1971 Dodge Challenger Pace Car driven by Eldon Palmer veered out of control and slammed into the base of the photographers' stand.
Everyone survived, although some were seriously hurt.
The race carried on, and so did the live broadcast.
The pace car crash was only the first in a series of devastating crashes.
In one of them, after more than 160 laps, Bobby Unser and Mike Mosely crashed into two disabled cars.
Bobby's brother, Al, remained in the lead throughout and took the checkered flag on his 32nd birthday.
Back-to-back wins for only the fourth time in race history.
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