Las Vegas • The recipe for disaster in auto racing is hardly a secret. Start with a problematic racing layout, mix in a field of expert drivers with rookies and rusty ones, put millions of dollars on the line and then add speed. Lots of speed.

On Sunday, the recipe produced one of the worst crashes in the history of IndyCar racing: a 15-car smashup that left the British driver Dan Wheldon, a two-time winner of the Indianapolis 500, dead at 33.

The problematic track was Las Vegas Motor Speedway, a steeply banked 1 1/2-mile oval more suited to stock car racing. The first IndyCar race run there in 1996 was plagued by crashes, and the two subsequent races there proved no safer.

"There's zero margin for error," James Hinchcliffe, the driver who said his car started the deadly crash, said in its aftermath. "Zero time to react."

The influence of money came in the form of a $2.5 million bonus Wheldon would have won if he had pulled off what many drivers regarded as little more than a dangerous stunt: agree to start at the back of the pack and see if he could thread his way through slower, less-experienced drivers to win.

Wheldon, who was wildly talented but had barely raced in 2011, acknowledged beforehand that the money was why he risked racing rusty.

And then there was speed. Practice runs had yielded high speeds and at least one serious crash — rookie James Jakes hit a wall Friday at more than 220 mph. Wheldon — "I'm hitting 221 mph on the backstretch," he said after a practice session Friday — told others that he felt a bit overwhelmed at those speeds, in a largely unfamiliar car.