China, as did gunpowder. In fact, that was the first use for gunpowder.

China, about 2,000 years ago. http://www.chemsoc.org/ExemplarChem/entries/2004/icl_Gondhia/history.html

China.

"Fireworks originated in China some 2,000 years ago. The most prevalent legend has it that fireworks were discovered or invented by accident by a Chinese cook working in a field kitchen who happened to mix charcoal, sulphur and saltpeter (all commonly found in the kitchen in those days). The mixture burned and when compressed in an enclosure (a bamboo tube), the mixture exploded. Some sources say that the discovery of fireworks occurred about 2,000 years ago, and other sources place the discovery sometime during the 9th century during the Song dynasty (960-1279), although this could be confusion between the discovery of gunpowder by the cook and the invention of the firecracker. Some sources suggest that fireworks may have originated in India, but in the October 18, 2003, online edition of The Hindu, an Indian national newspaper, the Chinese are credited with the discovery of gunpowder. A Chinese monk named Li Tian, who lived near the city of Liu Yang in Hunan Province, is credited with the invention of firecrackers about 1,000 years ago. The Chinese people celebrate the invention of the firecracker every April 18 by offering sacrifices to Li Tian. During the Song Dynasty, the local people established a temple to worship Li Tian. " Source and further information: http://www.fireworks.com/safety/fireworks-history.asp

in hell

China, among many other things.

IN CHINA