LAGOS, Nigeria—A 21-story apartment building under construction collapsed in an upscale area of Nigeria’s largest city, killing at least three people and leaving dozens more missing, officials and witnesses said on Monday. Lagos Police Commissioner Hakeem Odumosu confirmed the deaths, but added that three survivors had been pulled from the rubble in Ikoyi by Monday evening. Officials arriving at the scene were confronted by crowds of people venting their anger that rescue efforts started several hours after the collapse. Olayemi Bello told The Associated Press that five of his friends were trapped in the building and he feared the worst. “When they work finish, they will come outside and they will play with us and talk about the work,” he said. “Now, nobody. All of them are dead.” Construction worker Eric Tetteh said that he and his brother had managed to escape. But he estimated that more than 100 people …