Here is what Jim (169INDY) is talking about. During the start of the 1971 Indianapolis 500 the driver of the 1971 Dodge Challenger pace car missed his braking point and plowed into a temporary grand stand at the end of pit lane injuring several photographers.
Synopsis according to Wikipedia:
"For 1971, none of the Big Three auto manufacturers chose to supply pace car for the Indianapolis 500, as the muscle car market had dried up and marketing efforts were shifted elsewhere. Four local Indianapolis-area Dodge dealers, spearheaded by Eldon Palmer, stepped up to supply the fleet of pace cars. The vehicle chosen was the Dodge Challenger 383-4V. Palmer was chosen to drive the pace car at the start of the race.
In preparation for the race, Palmer supposedly set up an orange flag (sometimes reported as an orange traffic cone) in the pit lane to provide himself with a braking reference point. However, there has been some dispute regarding the existence of the marker at all. During the parade and pace lap, Tony Hulman, ABC broadcaster Chris Schenkel, and John Glenn served as passengers in the car. Palmer practiced the run the day before the race.
As the field came down the main stretch for the start, Palmer pulled into the pits and accelerated down the pit lane. Palmer continued to accelerate, under the impression he was required to cross the start/finish line in the pit area prior to the race cars doing so out on the track. His reference flag (or cone) had been removed and he missed his planned braking spot. Moving upwards of perhaps 125 mph, Palmer realized he was going too fast, and rather than perilously veering back on to the racing surface, he stood on the brakes (the car was equipped with drum brakes) and lost control. The car swerved and skidded to the end of the pit lane, and crashed into a photographers' stand. The stand toppled and collapsed, injuring 29 people, but no one was killed. Dr. Vicente Alvarez, a freelance photographer from Argentina, was one of two on the stand who were seriously injured. Alvarez survived, and died in the late 1990s. Tony Hulman suffered a sprained ankle, and a shaken Schenkel sat out the remainder of the ABC broadcast.
Palmer maintained possession of the car, and eventually it was repaired and restored. Indiana businessman Steven Cage purchased the vehicle in 2006, and it currently is displayed at his RPM Collection in Fishers, Indiana. Reactions of the accident were very critical afterwards, and for the next several years, the pace car drivers selected were either former Indy drivers or people with racing experience."
Footage of the crash can be seen here:
https://www.youtube.com/watch?v=uekPw_egDqY