There are many elephant threats that have significantly depleted the elephant population. The largest of the threats has been the ivory trade as ivory is only found in elephants as their tusks are made of ivory. For many years elephants were strictly hunted for these treasures and because of the elephant’s natural long lifespan they do not breed quickly. Therefore the population cannot be built up quickly.
The vast majority of elephants were killed for their tusks as they were the only source of ivory. Most countries have banned elephant hunting but a few still allow hunting by permit only.
Untold numbers of elephants had to die for this to be possible.
Read the full article about the very real threat of elephant extinction here