A round circle of smoke coming from the mouth of the Etna volcano is seen in the sky during an eruption on the southern Italian island of Sicily April 11, 2013. Mount Etna is Europe's tallest and most active volcano. (Photo by Antonio Parrinello/Reuters)

A visitor looks at a sculpture entitled “Couple Under an Umbrella, 2013” by artist Ron Mueck during the press day for his exhibition at the Fondation Cartier pour l'art contemporain in Paris April 15, 2013. (Photo by Charles Platiau/Reuters)

Migrants ride on top of a northern bound train toward the US-Mexico border in Juchitan, southern Mexico, Monday, April 29, 2013. Migrants crossing Mexico to get to the U.S. have increasingly become targets of criminal gangs who kidnap them to obtain ransom money. (Photo by Eduardo Verdugo/AP Photo)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

People visit the art installation “Machine Memories: Space” by Turkish artist Refik Anadol in the exhibition at Pilevneli Art Gallery in I​stanbul, Turkey, 22 March 2021. The exhibition runs until 25 April. (Photo by Sedat Suna/EPA/EFE)

Women clash with police officers behind riot shields during a protest in support of Victoria Salazar, a Salvadoran woman who died after a Mexican female police officer was seen in a video kneeling on her back, in Mexico City, Mexico on April 2, 2021. (Photo by Raquel Cunha/Reuters)

Indian holy men, or Naga Sadhu, ride a motorbike on their way to take a holy dip in the Ganges River during the Kumbh Mela at Haridwar, Uttarakhand, India, 14 April 2021. Thousands of pilgrims gather for the mass Hindu pilgrimage which occurs every twelve years and rotates among four locations. (Photo by Idrees Mohammed/EPA/EFE)

Military Personnel sing and dance during celebrations for Independence Day in Dakar on April 4, 2022. Senegal Celebrates its sixty second Independence Day after gaining independence from France in 1960. (Photo by John Wessels/AFP Photo)