Dan Wheldon, one of IndyCar's most popular drivers, died Sunday, the cause of death being revealed by a coroner Monday as head injuries after a 15-car crash.

Tuesday, two days after Wheldon died at the Las Vegas Motor Speedway, the reaction has been swift and the questions have piled up. Could this have been prevented? If not, what are the steps needed for future prevention?

With the auto racing industry, whether in IndyCar or NASCAR racing, the possibility of such a horrific end to a race is ever-present. The questions and the uproar, though, only come when the drastic occurs.

The last time was 10 years ago, when the racing world lost another of its biggest names with Dale Earnhardt's death in the last lap of the Daytona 500.

When Earnhardt died, it was a shock felt beyond the racing community. He was the fourth driver to die in a span of 11 months then, but the name recognition had its effect. Casual fans, and even observers not keenly interested in racing, began to take notice.

The resulting investigation -- both by police and NASCAR -- led to changes in the sport for the betterment of safety. NASCAR made use of the HANS (Head and Neck Support) device mandatory; before Earnhardt's death, it was only optional.

Earnhardt's reported torn seatbelt made many races go from a five-point safety harness to a six-point harness. And tracks installed a soft wall, the SAFER (Steel and Foam Energy Reduction) Barrier. It is supposed to make tracks, well, safer by absorbing some of the energy of crashes and reduce the impact.

All of these changes are nice, but all of them are patches on the issue. The NASCAR investigation revealed one thing: that one thing, in fact, wasn't completely responsible for Earnhardt's death, and that there wasn't a simple patch.

With IndyCar racing and Wheldon's death, there may even be more issues to consider. Like racing on oval tracks; many have called for it to cease, including NASCAR champion Jimmie Johnson.

IndyCar chairman Randy Bernard, though, told The Associated Press two weeks ago that racing on ovals is something he thinks is a main draw that differentiates his motorsport from others.

You have to have your own niche, Bernard told The AP. What we came up with is we want to be known as the fastest race car with the most versatile driver in the world. No one runs the speeds we do with the versatility -- the ovals, the super ovals, the short ovals, road and street and we run in the rain. I love that.

If Bernard wants to keep ovals with high banking, he must figure out a way to make racing safe.

Already, drivers like Alex Tagliani are coming out and advocating for change, which is a good sign. Criticism from the inside means much more than that from the outside.

Other drivers have called for improvements to the catch fencing (which would be similar to the SAFER barriers), which gave Wheldon's cockpit a direct hit, according to The AP.

Finally, former Formula One driver David Coulthard said IndyCar should limit speeds in a column in The Daily Telegraph of London.

There is no need, in my opinion, to be racing at 225 mph, wheel-to-wheel, around mostly oval circuits, Coulthard wrote. You don't need to be doing that to entertain the crowds.

No doubt there will be changes to make IndyCar a safer racing circuit. But if there's anything NASCAR's changes have proven, though, it's that death simply cannot always be prevented, no matter the number and gravity of the changes. Because even after the changes that resulted from Earnhardt's death, four NASCAR drivers have died.