Complex sentence: In the 1955 Indianapolis 500, he stopped in a futile attempt to help Bill Vukovich when Vukovich's car crashed and burned during the race, and is the only driver in Indy 500 history to stop a non-damaged car to help another driver.
Split into simpler sentences: In the 1955 Indianapolis 500, he stopped his car in a futile attempt to help Bill Vukovich when Vukovich's car crashed and burned during the race. He is the only driver in Indy 500 history to stop a non-damaged car to help another driver.