LAGOS, Nigeria—A gas explosion in Lagos, Nigeria’s biggest city, on Tuesday killed at least five people, including a child, an emergency services official told The Associated Press. “There are four adults dead—three males and one female—and a 10-year-old boy died in the incident,” Ibrahim Farinloye of the National Emergency Management Agency said, adding that rescue operation is still ongoing. The fire broke out after a cylinder exploded at a gas shop in the densely populated Mushin area of Lagos. It was extinguished in about one hour and “we were able to rescue 10 people alive and they have been treated and discharged on the spot,” said Olufemi Oke-Osanyintolu, director-general of the Lagos State Emergency Management Agency. The cause of the explosion is not known yet but authorities are suspecting one of the gas cylinders exploded as a result of a fire close to the gas shop and work being done …