Who was to blame? An official inquiry called it a "racing incident," and to this day racing historians debate the issue. A British documentary now on DVD, "The Deadliest Crash," examines the event--including some startling and heart-stopping images captured that day -- and shows how drivers Levegh, Mike Hawthorn and Lance Macklin jockeyed for position until, at the fatal point, Levegh's car strikes Hawthorn's Jaguar and is sent airborne.
What's not debatable is that the disaster nearly led to the suspension of motorsports racing in Europe and initiated the culture of racing safety that exists today. After the season, Mercedes-Benz pulled out of racing officially for some three decades, while entire sanctioning bodies revised their safety regulations for circuits. American John Fitch, Levegh's co-driver for the '55 event, went on to make safety innovation his life's mission. He invented the "Fitch Barrier" system, a sand- or water-filled barrel system that disperses kinetic energy in a crash. They are commonly used today alongside highways and in motor racing, including at the 24 Hours of Le Mans today.
There's more information about the DVD at http://www.big-pic.co.uk/deadliestcrashquotes.html. Currently it's available as a Region zero disc, which means it will play on most computers and some conventional DVD players.