A woman smokes a mask bong on the final day of Hempfest, Seattle's annual gathering to promote the legalization of marijuana, on August 17, 2014. (Photo by Jordan Stead/Seattlepi.com)

Pakistani students look out from a vehicle on their way to school near the Army Public School which was targeted by Taliban militants last year, in Peshawar, Pakistan, Monday, January 12, 2015. (Photo by B.K. Bangash/AP Photo)

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

“On 24 July 2010, a stampede at the 2010 Love Parade electronic dance music festival in Duisburg, North Rhine-Westphalia, Germany, caused the death of 21 people. At least 510 more were injured”. – Wikipedia

Photo: Wall art and candles are pictured in the tunnel of the 2010 Loveparade disaster near to where many of the deaths occurred on the first anniversary of the tragedy on July 24, 2011 in Duisburg, Germany. (Photo by Thomas Starke/Getty Images)

The world's biggest wild animal farmer, Carr Hartley of Rumuruti in Kenya, sells animals to zoos, circuses and film companies. (Photo by Maxim Ruston/BIPs/Getty Images). November 1956

Maharashtrian women dressed in traditional costumes attend celebrations to mark the Gudi Padwa festival in Mumbai March 21, 2015. The festival marks the beginning of the new year for Maharashtrians and is celebrated widely in Maharashtra and in the Konkan region. (Photo by Danish Siddiqui/Reuters)

A woman whose livelihood depends on selling recyclable wastes collects trash from a dumping site while surrounded by Marabou storks on the outskirts of Uganda's capital Kampala March 31, 2015. (Photo by James Akena/Reuters)

Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)