A simulated casualty is evacuated during an emergency services exercise at the disused Aldwych underground station on February 22, 2012 in London, England. Operation Forward Defensive aims to test the response to a terrorist incident on the London Underground network during the 2012 Olympic Games. (Photo by Peter Macdiarmid/Getty Images)

Imaan Hammam and Rihanna attend the FENTY x Webster Pop-up Cocktail at The Webster on June 18, 2019 in New York City. (Photo by Dimitrios Kambouris/Getty Images for Fenty)

A resident walks through heavy snowfall in the Kashmiri city, India on November 11, 2019. There have been several fatalities as the winter weather arrives in the region. (Photo by Saqib Majeed/Barcroft Media)

A member of Iraqi rapid response forces fires a rocket launcher during a battle with Islamic State militants in the district of Yarimja in southern Mosul, Iraq, January 18, 2017. (Photo by Alaa Al-Marjani/Reuters)

Models backstage ahead of the St George New Generation show at Mercedes-Benz Fashion Week Australia 2015 at Carriageworks on April 16, 2015 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

“«The Red Detachment of Women» (simplified Chinese: 红色娘子军) is a Chinese ballet which premiered in 1964. It is perhaps best known in the West as the ballet performed for U.S. President Richard Nixon on his visit to China in February 1972. Adapted from the earlier film of the same title under the personal direction of Zhou Enlai, which in turn adapted from the novel by Liang Xin, it depicts the liberation of a peasant girl in Hainan Island and her rise in the Chinese Communist Party”.

A billboard for JELL-O stands at the corner of Grand Street and West Broadway on August 2, 2011 in New York City. The billboard acts as a mood-meter by analyzing Twitter and guaging the number of happy and sad emoticons used at any given moment, causing the billboard's face to change between a smile and a frown. (Photo by Andrew Burton/Getty Images)

The Grand Canyon Skywalk is a transparent horseshoe-shaped cantilever bridge and tourist attraction in Arizona near the Colorado River on the edge of a side canyon in the Grand Canyon West area of the main canyon. USGS topographic maps show the elevation at the Skywalk's location as 4,770 ft (1,450 m) and the elevation of the Colorado River in the base of the canyon as 1,160 ft (350 m), and they show that the height of the precisely vertical drop directly under the skywalk is between 500 ft (150 m) and 800 ft (240 m).