On that terrible morning, when American Airlines Flight 11 hit the North Tower of the World Trade Center, Victor Wald , 50, was working in his 84th floor office at the small brokerage firm, Avalon Partners. Like his colleagues, he raced for the exits, and scrambled down the stairs. But, having suffered from rheumatic fever as a child, he collapsed in exhaustion on the 53rd floor, as frantic workers from the building’s upper floors hastily passed him by. Harry Ramos , 46, the head trader at the small investment bank, May Davis Group, who worked on the 87th floor, saw him on the stairs, and stopped.

They had never met, had no friends or relatives in common. But Ramos saw Wald and said, “I won’t leave you.” Ramos managed to coax Wald down to the 36th floor, where they sat together as the building collapsed.

“I won’t leave you,” he said. Minutes later, the two died.

When the National September 11 Memorial opens this fall, on the tenth anniversary of that world-changing day, the two friends? names will be inscribed next to each other on the granite wall surrounding the Memorial Garden’s fountains.

Their adjacency is product of a masterful bit of programming undertaken by the New York media design firm Local Projects, which took 1,800 requests from families of the 3,500 9/11 victims, and created an algorithm that let them be grouped by affinity: firefighters with firefighters, cops with cops, all the members of each of the flights, first responders, or just pals.

This afternoon, as President Obama made his way to Manhattan to lay a wreath at the World Trade Center site, the 9/11 Memorial President, Joe Daniels, unveiled the web site that displays the final arrangement. Names.911memorial.org provides wayfinding for each of the victims. It also provides brief biographical information provided by next-of-kin. The same application will be available on mobile smartphones, tablet computers, and electronic kiosks when the plaza of the Memorial opens on Sept. 11, 2011.

“It’s the connections in our lives that matter the most,” said Daniels at this morning’s breakfast meeting on the 40th floor of 7 World Trade Center, overlooking the 9/11 site. “These names, inscribed in bronze, are the heart of the experience.”

“It’s the connections in our lives that matter the most.”

Conventional memorial design dictates that names are listed alphabetically or chronologically. That makes people easy to find, but tends to dilute the meaning that attaches to affinity. With this new program, bands of brothers, families, and co-workers, can be remembered as part of a group that meant the world to them in life and united them in death.