From CNN. Story by By Briana Duggan, Robyn Kriel and Mayra Cuevas.

Twelve ivory towers burned in Kenya on Saturday, sending thick plumes of ash and smoke over Nairobi National Park as elephant and rhino tusks smoldered.

A rainy Saturday afternoon brought together heads of state from several African nations and hundreds of onlookers to watch Kenyan President Uhuru Kenyatta set fire to over $172 million worth of illicit wildlife goods.

A somber mood took over the crowd as the event began. Bright red embers bloomed inside the 10-foot high by 20-foot wide pyres, turning the coveted white ivory tusks to nothing more than charred animal remains.

This was the most significant demonstration against poaching in the region and the largest burn of illegal wildlife products in history.

Every 15 minutes, an elephant is killed for its tusks. And some 1,338 rhinos were poached in Africa last year, a record number and the sixth year in a row that the number of poaching incidents has increased.

Critics worried it would send the price of ivory in the black market up but conservationist Richard Leakey told the crowd at the burn ceremony that prior burnings have led to a dramatic drop in prices.

Kenya’s tourism, based mostly around its wildlife, makes up about 12 percent of the country’s GDP. Over its life, a live elephant generates 76 times more in tourism revenue than it does for its ivory, according to the David Sheldrick Wildlife Trust, an elephant rescue and rehabilitation group.

“The rising value of elephant ivory trade, illegally on the international market, has resulted in a massacre in the rainforest of Africa,” Kenyatta told the crowd. “In 10 years in Central Africa we have lost as many as 70 percent of the elephants. Unless we take action now we risk losing this magnificent animal.”

It took Kenya’s Wildlife Services 10 days to build the crematorium that contained the 105 tons of elephant ivory, 1.35 tons of rhino horn, exotic animal skins and other products such as sandalwood and medicinal bark. This was Kenya’s fourth such burn in a practice that goes back to 1989 — an idea hatched to combat the worsening poaching crisis.

The tusks from about 8,000 elephants would be worth more than $105 million on the black market, according to wildlife trade expert Esmond Bradley Martin. The rhino horn from 343 animals, would be worth more than $67 million.

But the Kenyans say that the stockpile is not valuable — it’s worthless.

“From a Kenyan perspective, we’re not watching any money go up in smoke,” Kenya Wildlife Service Director General Kitili Mbathi said. “The only value of the ivory is tusks on a live elephant.”

Critics of the burn worry the destruction of this stockpile will increase the price of ivory in the black market and encourage more poaching.

“That is an ignorant idea,” Leakey told the crowd at the burn ceremony. “We did it before and prices went from $300 down to $5 within three months of that fire. It is quite shameful the slaughter of these wild species in a world that seems hell bent on destroying itself anyway — let’s give our support to nature and the endangered species.”

“Today’s event allows Kenya to send a very public message to the international community and here in Kenya, that it does not tolerate and it will not tolerate the illegal trade in wildlife,” John Scanlon, spokesman for the Convention on International Trade in Endangered Species, told the crowd.

“Not only it has a devastating impact on the animal themselves and their ecosystem but it has an impact on security, on livelihoods and on economy,” said Scanlon.

At Nairobi National Park, the clouds of smoke have turned the sky a fetid gray shade of green. Organizers hope this image, and stigma, will be burned into memory forever.

Read more at  CNN.