Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Shokyo Miura, a Buddhist monk and one of the on-site priests, poses for pictures outside Tera Cafe in Tokyo, Japan, April 1, 2016. At first glance, the cafe, which also serves alcohol, looks like any other except for an altar next to the countertop bar with a Buddha statue set against a gold backdrop. The menu confirms this is something different. It lists classes for 1,500 yen ($14) in weaving prayer beads, calligraphy with sutras, or lines of scripture, and consultations with a Buddhist priest. (Photo by Yuya Shino/Reuters)

Pablo Holcer tests out a VR system made by Neurable that allows the user to control with their thoughts as the EEG headset interprets thoughts into actions in the VR environment at SIGGRAPH 2017 in Los Angeles, California, July 31, 2017. (Photo by Mike Blake/Reuters)

Women in yukatas, or casual summer kimonos, take their selfie in front of paper lanterns during the annual Mitama Festival at the Yasukuni Shrine, where more than 2.4 million war dead are enshrined, in Tokyo, Japan July 13, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Waves triggered by Typhoon Hato are seen in Hong Kong, China on August 23, 2017. A powerful typhoon barreled into Hong Kong on Wednesday, forcing offices and schools to close and leaving flooded streets, shattered windows and hundreds of canceled flights in its wake. Typhoon Hato came within 60 kilometers (37 miles) of Hong Kong, close enough to be considered a direct hit under Hong Kong's storm warning system. It was headed toward the western side of mainland China's Pearl River Delta. (Photo by Tyrone Siu/Reuters)

Smoke and flames rise over a warehouse storing ammunition for multiple rocket launcher systems at a military base in the town of Kalynivka in Vinnytsia region, Ukraine September 27, 2017. Ukrainian officials say they have evacuated more than 30,000 people after a fire and ammunition explosions, at the military base on Tuesday. (Photo by Gleb Garanich/Reuters)

A model presents a creation by British designer Vivienne Westwood as part of her Spring/Summer 2018 women's ready-to-wear collection show during Fashion Week in Paris, France on September 30, 2017. (Photo by Charles Platiau/Reuters)