The deadly realities of racecar driving

The death of seven-time NASCAR champion Dale Earnhardt led to sweeping safety improvements in NASCAR, which has not suffered a fatality since. Now, 10 years after Earnhardt's death shook all motorsports series to its core, IndyCar has been devastated by the loss of Dan Wheldon.

The 33-year-old Wheldon, one of the most well-liked drivers in the paddock, died Sunday after his car became ensnarled in a fiery 15-car pileup, flew over another vehicle and landed in a catch fence just outside turn 2 at Las Vegas Motor Speedway.

It was IndyCar's first fatal accident since Paul Dana died during a morning warmup at Homestead in 2006. Formula One's last fatality was Ayrton Senna in 1994.<