Adam and the others—she estimates that there were more than forty of them in the store—piled into a back room. Among them were several white people. “If they come in and they see white people, they won’t care, they’ll kill all of us,” she said. There was a small cubicle with the store’s surveillance-camera monitors in it. She told the white customers to go in it and hide, and reminded everyone to turn off their cell phones or put them on silent mode. “As we were sitting there, you could hear everything.” Between bursts of gunfire and explosions, she heard what sounded like people moving around in air ducts. She wanted to call out to them. But a man who identified himself as U.N. security personnel said it could be the assailants. So they waited, in silence. They passed around cups of water and held each other’s hands.

Adam’s husband, in Hong Kong, texted her. “He said ‘These are terrorists, and they’re killing anybody who’s non-Muslim. Tell all the foreigners with you not to go out,’” she said. “I started crying at that point, when I realized it was al-Shabaab. I suspected before, but you know you self-doubt. When I heard it on a text coming from Hong Kong, then I know it’s in black and white.”…

Men with large rifles or machine guns fired into the crowd, he said. Some children fell, shot; others lay down. He described the gunmen firing into their backs. One of the attackers took up a stone and slammed a man, who was holding a child, in the head. Then he picked his gun back up and fired more.

The men stopped shooting. One yelled, in Swahili, “Kama wewe ni Muslamu amka uende!”—“If you’re Muslim, get up and go!” Some people got up and left. Then the gunmen opened fire again. Done, they ran into the mall. Njoroge went into another stall, away from the window, and crouched on the toilet.