April 15 Runners continue toward the finish line of the Boston Marathon as an explosion erupts near them. Two simultaneous explosions ripped through the crowd, killing at least two people and injuring dozens on a day when tens of thousands of people packed the streets to watch the world-famous race. Dan Lampariello/Reuters, via Landov April 15 An emergency responder and two volunteers, including Carlos Arredondo, center, push Jeff Bauman in a wheelchair after he was injured in an explosion near the finish line of the Boston Marathon. Charles Krupa/AP April 16 Neighbors sit outside the house of Krystle Campbell’s parents. Campbell was killed in Monday’s explosions at the finish line of the Boston Marathon. Michael Dwyer/AP April 18 President Obama and first lady Michelle Obama arrive to board Air Force One. The Obamas were heading to Boston to mourn victims of the deadly marathon attacks. Jewel Samad/AFP/Getty April 13 South Korean rapper Psy performs during his “Happening” concert, where he unveiled his next single, “Gentleman,” in public for the first time. Lee Jae-Won/Reuters, via Landov April 15 A North Korean soldier guarding the entrance to the Kumsusan mausoleum, where the bodies of the late leaders Kim Il-sung and Kim Jong-il lie embalmed, looks back through the doors of the main gate. North Koreans turned out on Monday to mark the 101st birthday of Kim Il-sung. David Guttenfelder/AP April 16 Israelis watch an air show during Independence Day, marking 65 years since the founding of the state in 1948. Dusan Vranic/AP April 16 An Afghan refugee boy, right, launches a kite, while other children play nearby, in a poor neighborhood on the outskirts of the city. Pakistan hosts more than 1.6 million registered Afghans, the largest and most protracted refugee population in the world, according to the U.N. refugee agency. Muhammed Muheisen/AP April 13 In this photo released by Indonesian police, the wreckage of a crashed Lion Air plane sits on the water near the airport. The plane, carrying more than 100 passengers and crew, overshot a runway on the Indonesian resort island and crashed into the sea, injuring nearly two dozen people, officials said. Indonesian Police/AP April 17 The coffin of former British prime minister Margaret Thatcher is carried by the Bearer Party as it arrives for her funeral service at St Paul’s Cathedral. Thatcher, who was Conservative prime minister between 1979 and 1990, died on April 8 at the age of 87. Stefan Wermuth/Reuters, via Landov April 18 A vehicle is seen near the remains of a fertilizer plant burning after an explosion at the plant, near Waco. The deadly explosion ripped through the fertilizer plant late on Wednesday, injuring more than 100 people, leveling dozens of homes, and damaging other buildings, including a school and nursing home, authorities said. Mike Stone/Reuters, via Landov April 18 Firefighters conduct search and rescue of an apartment destroyed by an explosion at a fertilizer plant. A massive explosion at the West Fertilizer Co. killed as many as 15 people and injured more than 160, officials said overnight. LM Otero/AP April 15 Palestinian farmers harvest wheat on a farm near the West Bank city. Mohammed Ballas/AP April 13 Igmar Orellana, center, dances to Beyoncé’s “Move Your Body” music video, which was created as part of Michelle Obama’s Let’s Move campaign, during the Network for a Healthy California–LAUSD’s Community Nutrition Workshop, where students surprised 100 parents with lessons and activities to promote healthy living. Rene Macura/AP