INDIANAPOLIS (AP) Rich MacDonald was just a kid, trying to find his dad's race number on the big screen through the flames and black mushroom clouds choking the track.
Only 6 years old, MacDonald, his grandfather and uncle had gone to the LA Sports Arena to watch the 1964 Indianapolis 500 live on closed-circuit television. Just two laps into the race, there was a fiery wreck and it was clear something had gone horribly wrong at Indianapolis Motor Speedway.
Rich MacDonald still remembers trying to find out if his father, American road racing champion Dave MacDonald, was in the wreckage.
''I really didn't get it. There was lots of fire, lots of smoke,'' MacDonald said. ''I remember seeing little clues. I knew my father's number was 83. And 83 was up there. My grandfather grabbed my uncle and me out of the stadium and into the lobby area. I knew at that point there was a problem.''
MacDonald would die later that afternoon and driver Eddie Sachs also was killed, a grisly reminder that the race has always been a life-and-death business.
Yes, the Indy 500 is ''The Greatest Spectacle In Racing,'' and Mario and Dario and milk and balloons have built an event steeped in festive tradition as it prepares to celebrate its centennial this weekend. But the race is also marked by tragedy. Just 12 laps into the inaugural race in 1911, mechanic Sam Dickson became the first to die and he certainly wasn't the last.
Drivers, mechanics, fans, even a little boy standing across the street from the track long ago - all are part of the 500's saddest chapter, painful memories of just how dangerous racing on the bricks and asphalt has been over the years.
At least 66 people have died because of auto racing since 1909 at the site, including 40 drivers, 14 mechanics and nine spectators. The 1930s was by far the deadliest decade with 21 deaths, while the `50s and `60s each saw eight people perish.
Back in '64, Dave MacDonald had lost control of his car and slammed into the inside wall. His car exploded into a fireball and slid back onto the track. Sachs hit MacDonald's car head-on, and he was killed instantly, the track engulfed in so much fire and black clouds that it looked at IMS like a small town had burned down.
Nearly 2,000 miles away, Rich MacDonald tried to flip on a TV and watch the rest of the Indy 500 that would be won by A.J. Foyt. More than 50 friends and relatives had gathered at the family home in El Monte, California, many trying to give comfort to Rich and a younger sister.
''At 6 years old, you don't really comprehend your dad is dead,'' he said. ''All I knew was they kept talking about dad on TV. I remember distinctly trying to turn the race back on and people would turn it back on and usher me out of there.''
MacDonald's mother, Sherry, was at the track that day. Afterward, she withdrew from the racing community and could not imagine the idea of visiting the track again - until this year.
Rich MacDonald and Sherry; Sachs' son, Eddie III, and Angela Savage, daughter of Swede Savage, the last driver to die in the race (1973), will all travel to the speedway this week and hope to pose for a group photo on the track. Angela Savage was born three months after her father died.
MacDonald said the group hopes to walk on the famed track and find a spot to honor their fathers - and do it with a smile.
''We all had a loved one that was killed here, but it's not going to define our lives,'' Rich MacDonald said.
Now 78, Sherry MacDonald will make the trip for the first time after her son was invited to attend by a friend from the Gordon Pipers, a Scottish-inspired parade unit.
''After all these years, she can talk about it more,'' MacDonald said. ''This is the final step where she will be able to deal with it.''
The somber reality is that carnage on race day was once fairly common. And drivers are far from the only victims.
Consider the random cruelty of the race in the case of 12-year-old Wilbur Brink. He was killed while he played in his front yard on Georgetown Road when a tire sailed high over the fence and came bouncing across the street during the 1931 race after it came off the car of defending 500 champion Billy Arnold during a wreck. Brink is buried in Indianapolis at Crown Hill Cemetery, where the four founders of the Indy 500 are buried, along with other Indy 500 winners, drivers, mechanics and car owners.
Tragedy struck the 44th edition in 1960 in the stands, when a privately owned scaffold collapsed, killing two people and injuring at least 82. The last fan death came in 1987, when 41-year-old Lyle Kurtenbach was struck by a flying wheel from Tony Bettenhausen's car. Kurtenbach's widow filed a $9 million wrongful death lawsuit in federal court, later reaching an undisclosed settlement.
Savage was the last race-day fatality when his car slammed into an inside wall and exploded in flames. He died 33 days later. No driver has been killed in May at the speedway since pole-winner Scott Brayton in a fatal crash testing a backup car in 1996.
''It reminds you this is a very serious business we're involved in,'' said John Menard, owner of Brayton's car, back in `96. ''Scotty had a perfect race car, a perfect day, and a perfect track, and yet it reached out and bit him.''
Advancements in technology are credited with saving lives, with just four deaths at the speedway since 1982. After the MacDonald-Sachs crash, cars were fueled with less volatile methanol starting in 1965.
''It's considerably safer than it was 40 years, 30, even less,'' track historian Donald Donaldson said. ''It's nothing to do with the skill of the drivers. It's all about the equipment, the safety.''
The threat of a driver death still looms in an open-wheel race. Dan Wheldon, a two-time Indy 500 champion, was killed in a 2011 race in Las Vegas and driver Justin Wilson died from injuries suffered when he was struck by debris in a race last season at Pocono. His brother, Stefan Wilson, will race the Indy 500 in his honor.
''It used to be considered the death-defying or dare-devilish event,'' 2004 Indy 500 winner Buddy Rice said. ''We've seen in the past you can still get hurt. But it's not what it used to be. With all the safety stuff, it's made it great and way safer and better for everybody, but it's also lost some of the edge that wasn't there.''
Sid Collins, the voice of the Indianapolis 500 credited with coining the ''The Greatest Spectacle In Racing'' nickname, summed up the life-vs.-death dilemma in an on-air eulogy for MacDonald and Sachs all those years ago.
''Some men try to conquer life in a number of ways,'' he said. ''Race drivers are courageous men who try to conquer life and death and they calculate their risks. And with talking with them over the years, I think we know their inner thoughts in regards to racing. They take it as a part of living.''