A burning tank is in Daraa, on March 9, 2013. (Photo by Ali Abu-Salah/Reuters/Shaam News Network via The Atlantic)

Clearing skies await a tripod-toting photographer looking for a spot to capture the early-morning light at Portland Head Light, Thursday, January 17, 2013, in Cape Elizabeth, Maine. (Photo by Robert F. Bukaty/AP Photo)

A female hippopotamus named “Mali”, which means Jasmine, eats fruits arranged to look like a cake during her 50th birthday celebration at Dusit Zoo in Bangkok, Thailand September 23, 2016. (Photo by Chaiwat Subprasom/Reuters)

Iraqi army soldiers warm themselves next to a fire near the Qayara air base, south of Mosul, Iraq, Tuesday, November 1, 2016. The U.N. human rights office is lauding efforts by the U.S.-led coalition in the battle against the Islamic State group in Mosul. The office in Geneva says coalition flights over Iraq have largely succeeded in preventing IS from bringing in 25,000 more civilians to the city center, where the militant group has been using people as human shields as Iraqi forces advance on Mosul. (Photo by Felipe Dana/AP Photo)

Pakistani civil society activists release lanterns into the sky in Lahore on December 15, 2016, as they pay tribute to victims on the second anniversary of an attack on The Army Public School in the city of Peshawar. Taliban militants attacked on Pakistani Army Public School in Peshawar, killing 151 people mostly children on December 16, 2014. (Photo by Arif Ali/AFP Photo)

In advance of Fleet Week performances, the U.S. Navy Blue Angels and Team Oracle aerobatics pilot Sean D. Tucker fly over the San Francisco Bay during a photo flight on Thursday, October 5, 2017. (Photo by Noah Berger/AP Photo)

Students from CAS Ballet Theatre School stretch on the sidewalk Saturday, February 20, 2016, in Ann Arbor, Mich. (Photo by Junfu Han/The Ann Arbor News via AP Photo)

A hostage runs towards a police officer outside Lindt cafe, where other hostages are being held, in Martin Place in central Sydney December 15, 2014. Two more hostages have run out of the cafe at the center of a siege in Sydney, Australia's largest city, according to a Reuters witness at the site. The two women were both wearing aprons indicating they were staff at the Lindt cafe where a gunman has been holding an unknown number of hostages for several hours. Three men had earlier run out of the cafe. (Photo by Jason Reed/Reuters)