The race was won by A. J. Foyt, but is primarily remembered for a fiery seven-car accident which resulted in the deaths of racers Eddie Sachs and Dave MacDonald.

Jim Clark, who finished second the previous year, won the pole position[3] in the Lotus 34 quad-cam Ford V-8.

Clark's Lotus teammate Dan Gurney was later pulled from the race after experiencing similar tire wear.

Bobby Marshman led during the early stages of the race, at one point stretching his lead to as much as 90 seconds.

With Marshman, Clark, and Jones all out of the race, A. J. Foyt cruised to victory, leading the final 146 laps.

[11] The wheels were most notably enclosed in the front and the rear by streamlined bodywork, intended to take advantage of aerodynamic effects to increase top speeds.

The tanks each had a single bladder installed by the late Dave Zieger, in a fiberglass shell supported by the fill neck and a molded fiberglass body housing and a flat thin magnesium plate beneath the tank, braced by two steel straps hanging from the top rails of the frame.

An urban legend circulated that Thompson was boasting plans to drive the entire 500 miles without a pit stop, using an oversized fuel tank, but this has been proven false.

On Carburetion Day, MacDonald tested the car, with conflicting accounts on whether he ever drove with a full load of fuel.

[11] Another Formula One driver and future Indy 500 winner Graham Hill had actually tested the car at the speedway in 1963 but had refused to drive it because of its bad handling.

Rutherford later said, watching the behavior of MacDonald's car, he thought, "he's either gonna win this thing or crash.

"[16][17] Eyewitness accounts and film footage are inconsistent about the exact details of MacDonald's first two laps, but it is generally agreed he was attempting to pass many cars.

The car slid across the track and hit the inside wall, igniting the gasoline in the tank and resulting in a massive fire.

A lemon that had been on a string around Sachs's neck was found inside Rutherford's engine compartment after the crash.

The sense of gloom within the American racing community was further compounded when, just a week after the tragedy at Indianapolis, popular driver Jim Hurtubise was critically burned at Milwaukee.

Closure was not met until son Rich MacDonald began researching his father's career, with the DaveMacDonald.net Web domain since 2003 a tribute to his father's accomplishments and a family diary to the modern era, meeting Sachs's son Edward Julius III (known as Eddie Jr) on social media.

[21] Earlier in 2016, Rich MacDonald appeared in a podcast presented by Angela Savage, the posthumously born daughter of Swede (killed at the 1973 race), which struck a friendship between the two children of the fallen racers.

For the first time ever, the race was shown live, flag-to-flag, on closed-circuit television in theater venues across the county.

A few minutes of filmed highlights appeared a week later on ABC's "Wide World Of Sports" The race was carried live on the IMS Radio Network.

With the addition of WJAR-AM in Providence, Rhode Island, for the first time, the broadcast was carried by at least one affiliate originating in all 50 states.

[29] Charlie Brockman left the radio crew permanently in 1964 to take over anchoring the MCA closed-circuit television broadcast.