Gun enthusiasts look over Smith & Wesson pistols at the NRA Annual Meetings & Exhibits on May 21, 2016 in Louisville, Kentucky. About 80,000 visitors are expected to attend the three-day event. (Photo by Scott Olson/Getty Images)

Children ride in the trunk of a car on a flooded street in Sanaa, Yemen August 1, 2016. (Photo by Khaled Abdullah/Reuters)

Revellers wearing lanterns parade through the streets during the carnival procession of Basel, Switzerland, 15 February 2016. The traditional Morgestraich starting Monday morning after Ash Wednesday at 4 a.m. marks the kick-off of the Carnival of Basel. (Photo by Patrick Seeger/EPA)

Richard Coleby of Polaris falls over his quad into muddy waters during day one of the HydroGarden Weston Beach Race on October 14, 2017 in Weston-Super-Mare, England. (Photo by Michael Steele/Getty Images)

Tracy Sarita celebrates the sunrise during the Burning Man 2015 “Carnival of Mirrors” arts and music festival in the Black Rock Desert of Nevada, September 3, 2015. Approximately 70,000 people from all over the world are gathering at the sold-out festival to spend a week in the remote desert to experience art, music and the unique community that develops. (Photo by Jim Urquhart/Reuters)

(L-R) A man nicknamed "Barcelona", Alexey Bolotov and Alexey Jakushin drink vodka as they travel by a pioneer motorised railcar on their way to Kalach, Sverdlovsk region, Russia October 18, 2015. The "pioneer," a light auxiliary rail vehicle, is a popular form of transport among people who live along the Alapayevsk railway. In a remote corner of the Urals region at the end of a narrow-gauge railway is Kalach, population about a dozen. Three decades ago 600 people called the village home, but the local forestry industry suffered as the former Soviet Union imploded and people moved away in search of work. In Kalach today there are no telephones, no mobile reception and only a few hours of electricity a day. (Photo by Maxim Zmeyev/Reuters)

Members of the samba school of the Grupo Especial Independencia Tricolor participate in the carnival celebration at the Anhembi sambodrome in Sao Paulo, Brazil, 09 February 2018. (Photo by Sebastiao Moreira/EPA/EFE)

A girl holds her brother in her arm as black smoke rises after an oil well set on fire in the center of al-Kayyara town to the south of Daesh terror organization-held Mosul in Iraq on October 25, 2016. The oil well in the center of al-Kayyara town, which was set alight by retreating Daesh militants in advance of the Iraqi army's takeover of the town on August 24, 2016 has still not entirely been put out. The raw petrol which is still alight is creating black clouds above the city. The residents and wildlife beneath this polluting smoke cloud may find their health at risk. The effects of the fire in the town center on unprotected civilians' health can easily be seen on the hands and faces of children playing on the street. (Photo by dris Okuducu/Anadolu Agency/Getty Images)