1. William Bullock
Bullock invented the web rotary press, a printing press fed by a continuous roll of paper. In 1867, he either kicked or had his foot caught in one of the mechanisms, which resulted in an infected cut, gangrene, and eventually death.
2. William Nelson
A 24-year-old inventor who worked for General Electric, Nelson was killed while test-driving a motorized bike for which he invented a motor in 1903.
3. Henry Smolinski
Smolinski died in 1973 while test-piloting his flying car, the AVE MIZAR, the only product his company ever attempted to produce.
4. Horace Lawson Hunley
In 1863, Hunley engineered the first combat submarine for the Confederates during the Civil War. Despite the submarine having already sunk once, killing a majority of its crew, Hunley was aboard the CSS Hunley for its the second attempt at the Union blockade in Charleston, where he drowned along with the entirety of its crew.
5. Alexander Bogdanov
The physician invented blood transfusions in order to see if there were any rejuvenation effects on the human body. Bogdanov died in 1928 after his 12th transfusion, which was either infected or of the wrong blood type.
6. Harry K. Daghlian Jr. and Louis Slotin
The two physicists were running experiments on plutonium for The Manhattan Project, and both died due to lethal doses of radiation a year apart (1945 and 1946, respectively).
7. Karel Soucek
The professional stuntman developed a shock-absorbent barrel in which he would go over the Nigara Falls. He did so successfully, but when performing a similar stunt in the Astrodome, the barrel was released too early — and Soucek plummeted 180 feet, hitting the rim of the water tank designed to cushion the blow.
8. Max Valier
The rocket scientist invented liquid-fueled rocket engines during his time with the German rocketeering society Verein für Raumschiffahrt. He was killed in 1930 when an alcohol-fueled engine exploded on his test bench.