Mrs. Marie Graskamp of Milwaukee shows the different positions one might assume when entering the bomb shelter in Milwaukee September 3, 1958. This circular entrance is about three feet in diameter. This is the entrance (according to the builders) that would connect to the cellar of a home assuming the shelter was in the ground for added protection. If a bombing should occur, all members of family would proceed to the cellar and then through the circular port into the shelter. (Photo by AP Photo)

Trees are reflected on the surface of a lake in the Okefenokee swamp lands in Georgia, USA on October 21, 2017. (Photo by Chris Moore/Solent News & Photo Agency)

In this Monday, January 30, 2017 photo, wildfires straddle Chile's Dichato community. Strong winds are continuing to stoke the flames of raging wildfires in Chile, forcing the evacuation of more than 800 families in the coastal town of Dichato. (Photo by Esteban Felix/AP Photo)

A Sudanese man plays a local music instrument ahead of a meeting with Mohamed Hamdan Dagalo, also known as Himediti, deputy head of Sudan's ruling Transitional Military Council (TMC) and commander of the Rapid Support Forces (RSF) paramilitaries, in the capital Khartoum on June 18, 2019. (Photo by AFP Photo/Stringer)

Firefighters extinguish a fire in Kampar, Riau province on Indonesia's Sumatra island on August 13, 2019. Indonesian authorities are deploying thousands of extra personnel to prevent a repeat of the 2015 fires, which were the worst for two decades and choked the region in haze for weeks. (Photo by Wahyudi/AFP Photo)

A member of the riot police gets ready to repel the attacks of protesters during a protest against President Sebastian Piñera during the seventh day of protests against President Sebastian Piñera on October 24, 2019 in Santiago, Chile. Although President Sebastian Piñera announced measures to improve equality, unions called for a national strike and demonstrations continue as casualties are now at least 18. Demands behind the protest include issues like health care, pension system, privatization of water, public transport, education, social mobility and corruption. (Photo by Marcelo Hernandez/Getty Images)

A Syrian boy is comforted as he cries next to the body of a relative who died in a reported airstrike on April 27, 2016 in the rebel-held neighbourhood of al-Soukour in the northern city of Aleppo. The Syrian army was preparing an offensive to retake the whole of Aleppo, as fighting in the divided second city killed 38 civilians in a new blow for a tattered truce. Nearly 200 people have been killed in Aleppo in the past week as rebels have pounded government-held neighbourhoods with rocket and artillery fire and the regime has hit rebel areas with air raids. (Photo by Karam Al-Masri/AFP Photo)

In this September 16, 1983 file photo, actor and bodybuilder Arnold Schwarzenegger shows off his new U.S. citizenship papers as Maria Shriver, daughter of Sargent and Eunice Shriver, looks on at the Shrine Auditorium in Hollywood, Calif. (Photo by Wally Fong/AP Photo)