As al-Qaeda-linked terrorists threw grenades and fired automatic weapons, three plainclothes Kenyan police officers, lightly armed and wearing no bulletproof vests, helmets or other protective gear, worked their way to the roof of Nairobi's Westgate Mall and led a group of frightened shoppers to safety.
"I will be forever grateful for those three brave and selfless Kenyans," said Lyndsay Handler, an American who was among those rescued from the roof in the first hours of the siege that began on Saturday.
"Words cannot fully capture the depth of this gratitude, but anyone who has come close to losing a child or spouse can understand."
Undercover police officers armed only with pistols and walkie-talkies like those who rescued Handler and her husband and two-year-old daughter helped save countless lives in the initial minutes of the attack - heroics the New York native and others say have drawn too little attention.
Handler was in the complex with her husband, Nick, and their two-year-old, Julia.
Father and daughter were at the popular eatery, Artcaffe, when about a dozen al-Shabab militants descended on the upscale mall popular with foreigners and wealthy Kenyans and began firing indiscriminately.
Lyndsay, upstairs at a bookstore, headed to the roof, while Nick took shelter with Julia in a ground-floor storeroom for three hours until police came.
"It's hard to describe the relief I felt when I saw the doors to the storeroom open, and several incredibly brave plainclothes police, weapons drawn, motioned for us to leave," Mr Handler said.
"Perhaps it was not rational, but I instantly trusted these guys with our lives."
Ben Mulwa, a community organiser who was shot in the leg, said the first responders displayed immense courage in a chaotic and uncertain situation.
"They're only holding pistols. ... The other guys are walking with machine guns," he said. "They could have easily shot them. I found that extremely brave."
Individual acts of courage aside, however, Mulwa and other Kenyans questioned how prepared the country is to confront a large-scale attack.