Josephine Harris was 59, a Port Authority bookkeeper with a bad leg, walking down from the 73rd floor of the North Tower on September 11. By the time the firefighters of Ladder Company 6 found her in the stairwell, she was exhausted and crying. They had just been ordered out. The other tower was already gone. They did not leave her. Firefighter Bill Butler put her arm over his shoulder. “Josephine,” he said, “we’re going to get you out of here today.” Their pace became hers. Lower down she collapsed and told them to go on without her. They refused. Then the North Tower fell. Stairwell B held. The building peeled away around them. Fourteen people survived in that pocket: firefighters, a Port Authority officer, and Josephine. People who had passed them on the stairs did not. The men of Ladder 6 called her their guardian angel. They believed she slowed them just enough. Without her they would have been lower when it came down. Without them, she would not have made it out. When she died years later, those firefighters carried her coffin. One of them named a daughter after her. She was not trying to save anyone. She was a tired woman who could not walk any faster. That was enough.