The 57th 500 Mile International Sweepstakes was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Wednesday, May 30, 1973. The race was held over three days due to rain and suffered two major accidents. After 133 laps (332.5 miles), rain halted the race, and Gordon Johncock was declared the winner. It was the first of two Indy triumphs for Johncock (1973, 1982).

Going into the month, the mood was bright and excitement was high for record speeds. Competitors, media, and fans were eagerly anticipating the possibility of breaking the elusive and daunting 200 mph barrier during time trials. The month took a turn, however, when driver Art Pollard was killed during a practice session on May 12. Later that same day, Johnny Rutherford set a new track record during time trials. His best lap at 199.071 mph fell just short of breaking the much sought-after speed barrier. Despite Rutherford's headlines on pole day, the mood meanwhile around the garage area was becoming anxious and uncertain. Fears were growing about speeds and safety. Inclement weather was also interfering.

The race was scheduled for Monday May 28, but was aborted due to a major accident at the start. Driver David "Salt" Walther was critically injured and numerous spectators required hospitalization. Rain washed out the rest of the afternoon, and washed out any chance to hold the race on Tuesday May 29 as well. Only a fraction of the typical Indy crowd arrived to watch the race by the time it was run on Wednesday May 30.

The Wednesday race suffered two separate fatal accidents. The first involved driver Swede Savage; the second, pit crew member Armando Teran. Both occurred at lap 59 of the race. Due to the tragic circumstances, weather problems, rain-shortened finish, and overall glum mood during the month, the 1973 race is widely considered the worst year of the running of the Indianapolis 500. In contemporary accounts, the race had been called "jinxed" by Dan Gurney, Chris Economaki and Jim McKay.

National media opinions, as well as those from team owners and crew, were highly critical in the aftermath of the race, focusing namely on the lack of safety measures. The circumstances led to sweeping USAC rule changes made effective for the 1973 Schaefer 500 four weeks after the Indianapolis 500, as well as safety improvements to the Indianapolis Motor Speedway track itself which would be completed for 1974.

...
Wikipedia