Fireworks explode above Singapore's financial skyline at dusk as part of celebrations for the nation's 50th year of independence, Sunday, August 9, 2015, in Singapore. Singapore declared independence on August 9, 1965. (Photo by Wong Maye-E/AP Photo)

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)

In 1949, LIFE magazine sent famed photographer Nina Leen to document the daily life of a sassy troupe of young women who had run off and joined the famous Barnum & Bailey Circus in Sarasota, Fla. What developed was a portrait of a sisterhood formed over acrobatics that mixed high-flying wire acts with fashionable high-waisted shorts. Sarasota was once considered “the home of the American circus”. Here: an aerialist smoking while rehearsing for the Ringling Bros. and Barnum & Bailey Circus in Sarasota, FL in 1949. (Photo By Nina Leen/Time Life Pictures/Getty Images)

Pakistani Rangers (black) and Indian Border Security Force personnel (brown) perform perform during the daily beating of the retreat ceremony at the India- Pakistan Wagah Border Post, some 35 kms west of Amritsar on August 14, 2017. Pakistan celebrates its independence on August 14, one day before India' s independence day on August 15. (Photo by Narinder Nanu/AFP Photo)

The 27th Annual Tompkins Square Halloween Dog Parade was held on October 21, 2017. Thousands of costumed canines and spectators marched on Tompkins Square Park to participate in the countrys largest Halloween. (Photo by Erik McGregor/Pacific Press/LightRocket via Getty Images)

Father Angel (L), parish priest of San Anton Church blesses a dog during the celebrations of San Anton in Madrid, Spain on January 17, 2018. (Photo by Fernando Alvarado/EFE via ZUMA Press)

Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)

Brittany Ching dressed as a character from the sci-film “Avatar” at the annual Denver Comic Con at the Colorado Convention Center on June 16, 2016. (Photo by AndyCross/The Denver Post)