The two incidents have plunged the motorsport fraternity into deep shock as they came about within seven days. IndyCar racer Wheldon died on October 16 in Las Vegas while Moto GP rider Simoncelli succumbed to injuries he suffered during the Sepang event on October 24.
Formula One boss Bernie Ecclestone had avowed that F1 races are safe and the drivers endorsed his view by saying that they are not concerned about their safety.
The great Michael Schumacher said that drivers push the cars to the limit because this is what they love to do while Sahara Force India's Adrian Sutil remarked that F1 cars are safe.
They have a point as the last casualty that F1 witnessed was way back in 1994 when Austrian driver Roland Ratzenberger and three-time world champion Ayrton Senna died during the San Marino Grand Prix in Italy.
The question is what is it that makes Ecclestone and the drivers feel so confident about Formula One racing.
Ever since those deaths in Imola, F1's safety measures have undergone a sea change. From manufacturing of the car to clothes that drivers wear during the race, everything has been designed in such a way that a racer can escape with minor injuries even after even after suffering a crash.
Here we take a look what is required for making F1 materials, according to FIA.
The 'monocoque' or the tub of the car is a very strong component and it includes drivers' surviving cell. It is made from carbon fibre with up to 60 layers and no fuel, oil or water lines may pass through the cockpit. It is fitted in such a way that the driver is able to get out of the car within five seconds without having to remove anything except seat belts and steering wheel.
The width of the cockpit, where the drivers sits, must be 50 centimetres at the steering wheel, and 30 centimetres at the pedals. The cockpit opening must be 850mm long, at least 350mm wide at the pedals and 450mm wide at the steering wheel, with the rear half wider still at 520mm.
The rear 375mm of the cockpit's side walls must rise upwards at an angle of at least 16 degrees. This is done to reduce the risk of injury in the event of one car flying over the top of another and the edge of the cockpit must be enclosed in an energy-absorbing material with a thickness of at least 100mm.
The survival cell's flanks are protected by a 6mm layer of carbon and Zylon, a material used to make bullet-proof vests, to prevent objects such as carbon fibre splinters entering the cockpit.
The driver's seat is a single plastic cast and should not be a fixed part, and must be possible to remove the driver and seat as one after an accident, thus eradicating the risk of spinal damage.
All F1 cars must be equipped with a fire extinguisher system. This automatically spreads foam around the chassis and engine area in the event of fire and can also be operated manually by either the driver or marshals.
The cockpit is required to be equipped with a master switch that deactivates car's electronics, fuel pumps and rear light.
During a high-speed crash at the Canadian Grand Prix in 2007, Robert Kubica was subjected to more than 28 times the acceleration of gravity. This meant that his body effectively weighed two tons instead of 73 kilograms.
Thanks to the safety precautions, Kubica suffered only minor bruises.
Certain regulations have also been modified for the safety of the drivers such as to reduce the speed of cars and to facilitate overtaking, the double diffusers used since 2009 and the F-ducts developed in 2010 are prohibited.
To reduce the injury risk to neck and head in the event of a crash, F1 helmet must be supremely light - around 1250 grams is the norm - and strong. The helmets are subjected to extreme deformation and fragmentation tests and are made principally of carbon fibre, polyethylene and fire-resistant aramide, and is constructed in several layers.
Then there is the very important Head and Neck Support (HANS) system, introduced in 2003.
It consists of a carbon fibre shoulder collar which is intended to prevent stretching of the vertebrae and to prevent the driver's head from hitting the steering wheel.
As per FIA guidelines, driver clothing should be flame retardant so as to offer protection in the event of a fire.
The drivers use heavy, five layer, NASA-spec race suits. Nomex®, a fire-resistant, lightweight artificial fibre which undergoes thermal testing in the laboratory is used to make these suits.
It is subjected to an open flame with a temperature of 300 to 400 degrees celsius that acts on the material from a distance of three centimetres - only if it fails to ignite within 10 seconds can it be used in a driver's overalls.
The race suit features elastic cuffs on wrists and ankles and is made of two to four layers of Nomex®. A completed multi layered overall undergoes 15 washings as well as a further 15 dry cleaning processes before it is finally tested. It is then subjected to a temperature of 600 to 800 degrees celsius.
The critical level of 41 degrees celsius may not be exceeded inside the overall for at least 11 seconds.
The zip on the suit must also be able to withstand the same temperatures and must not melt or transfer heat close to the driver's skin.
Drivers in an overall can survive for 11 seconds in temperatures of 840 degrees celsius.
On all FIA-approved circuits a marshal and a fire extinguisher must be posted along both sides of the track every 300 metres.
There are rules to follow in the pit-lane also. Drivers must not cross the speed limit - normally 60 km/h during free practice and 100 km/h during qualifying and the race.
Drivers are fined during practice and qualifying if they break the limit, while in the race receive time-consuming drive-through penalties.