Earlier this week, we told you about the U.S. Fish and Wildlife Service's plans to destroy the country's stockpile of ivory, which the United States has been confiscating since the 1980s. The purpose: "By crushing its contraband ivory tusks and trinkets, the U.S. government sends a signal that it will not tolerate the senseless killing of elephants,” said Carter Roberts, President and CEO of World Wildlife Fund. That ivory crush took place yesterday in Denver in front of conservationists and representatives from African countries where elephants and rhinos are poached. According to the Wall Street Journal, the crushed ivory will now be stored in the warehouse of the Rocky Mountain Arsenal National Wildlife Refuge while they determine how best to use it to further education about elephant poaching. In recent years, ivory has shot up in value, with reports of it selling for more than $1,000 per kilogram in Beijing, and the restrictions on ivory commerce first implemented by the UN-backed Convention on International Trade in Endangered Species in 1989 have been relaxed to allow sell-offs by underfunded governments in 2008 and 2010. And while some have argued that the crush only makes ivory appear more scarce — and hence more valuable — U.S. officials vowed they would "work aggressively" to prosecute ivory traffickers, and encouraged other countries to destroy their own stockpiles as well. See the events of the day in our gallery above.