Automotive

William Nelson (1879-1903) was a General Electic employee who invented a new way to motorize bicycles. 

He then fell off his prototype bike during a test run.

Aviation

Ismail ibn Hammad al-Jawhari (1003 – 1010) was a Muslim Kazakh Turkic scholar from Farab, he attempted to fly using two wooden wings and a rope. 

 He leapt from the roof of a mosque in Nishapur and fell to his death.

Jean-Francois Pilatre de Rozier was the first know fatality in an air crash when his Roziere balloon crashed on June 15, 1785, while he and Pierre Romain were attempting to cross the English Channel.

Franz Reichelt (1879-1912) who was a tailor, fell to his death off the first deck of the Eiffel Tower while testing his coat parachute.  It was the first ever attempt with the parachute and he had told the authorities in advance that he would test it first with a dummy (referring to himself?)

Henry Smolinski died in 1973, when he was killed during a test flight of the AVE Mizar,

 a flying car based on the Ford Pinto and the sole product of the company he founded.

Michael Dacre died in 2009, after testing his flying taxi device

 designed to accommodate fast and affordable travel among nearby cities.

Medical

Thomas Midgley, Jr. (1889-1944) was an American engineer and chemist who contracted polio at age 51, leaving him severely disabled.  He devised an elaborate system of strings and pulleys to help other lift him from bed.  This system was the eventual cause of his death when he was accidentally entangled in the ropes of this device and died of strangulation at the age of 55.  He is more famous and infamous for developing not only the tetraethyl lead (TEL) additive to gasoline, but also chlorofluorocarbons (DFCs)

Physics

Marie Curie (1867-1934) invented the process to isolate radium after co-discovering the radioactive elements radium and polonium. 

She died of aplastic anemia as a result of prolonged exposure to ionizing radiation emanating from her research materials.

Punishment

Li Si (208 BC) was Prime Minister during the Qin Dynasty

and was executed by the “Five Pains” method which he had devised.

James Douglas, 4th Earl of Morton (1581) was executed in Edinburgh on the “Scottish Maiden”

which he had introduced to Scotland as Regent.

Space Exploration

Wan Hu, a sixteenth-century Chinese official, is said to have attempted to launch himself into outer space in a chair to which 47 rockets were attached. 

The rockets exploded and, it is said, neither he nor the chair was ever seen again……….perhaps it worked??!!?