Indycar: oval racing claims life of Dan Weldon

Indycars are upside-down aeroplanes, just like Formula One cars. But the significant difference is the nature of the tracks on which they race. Closed circuit "oval" racing depends on the ability of the car to sit in the slipstream of another fast moving vehicle without becoming destabilised. Destabilise an F1 car and it slithers onto the grass; destabilise a car on an oval and it hits another car (or several) and a solid wall.

The Las Vegas circuit is 1.5 miles long in a tri-corner layout.

33 year old Englishman Dan Weldon had started the last race of the season at the back of the field but within a dozen laps had worked his way up to the middle of the field when an accident happened in front of him: two cars touched lightly but that was enough to upset their balance. As carnage erupted, Weldon was unable to avoid it. His car flipped - and then rose above the recently installed "softer wall" to hit the catch fencing. Once airborne, cars do not slow down; once upside down, the aerodynamics operate in to create upward lift, instead of negative lift.

The track was covered with debris and the race was red-flagged, it being deemed to dangerous to continue to run under the safety car. When the final count was made, 15 cars had been involved in the incident, and Weldon was so badly injured that he died within a short time of the crash.

The race was abandoned.

Drivers, their teams and families were distraught. Weldon had not competed in this year's championship but had run in several races, reportedly because, despite a stellar career, he found it difficult to get funding. Mostly, he had been working on the development of the 2012 car which has additional safety features.

But those would not have helped in his own crash which demonstrates with graphic and brutal simplicity what it says on the sign at the entrance to every motor racing circuit in the world: motor racing is dangerous.