As reported by the Fortean Times; in March 1993 many elderly citizens committed suicide in Jiangsu Province, China. The reason for the sudden mass suicide was a change in the local laws.
Until that time, disposal of the dead was by burial - a Chinese tradition, ensuring that the body would arrive in the afterlife in one piece. This was similar in belief to the Egyptians' practise of mummification.
The local government passed a law stating that all corpses would be disposed of by cremation from April 1. And so, the deadline was set. Many people close to death had to beat this deadline. Methods used included overdoses of sleeping pills, hanging, drowning and jumping from bridges. A pharmacist who had sold out of sleeping pills reported that when he turned people down, they ran out into the street and jumped in front of trucks.
The report is particularly interesting, since ancient chinese monks would occasionally auto-cremate - that is, set fire to themselves having altered their diet
to include pine needles, herbs, resins, incense, and oils. This would make a fragrant sacrifice worthy of the gods' attention, and would place the body in a state where no further decay could take place - the same train of thought behind mummification.
The Fortean Times Book of Strange Deaths