The 9/11 Memorial is sure to be beautiful—a cascading waterfall in remembrance of that tragic day. It's also extremely thoughtful—instead of arranging the names in alphabetical order, the 9/11 Memorial will cluster people together who share bonds through friendship, work or incredible story.

So the 704 people from Cantor Fitzgerald who passed away will be grouped together, as will Harry Ramos and Victor Ward, two men who just met each other on the stairs on that fateful day. It's the work of an incredible algorithm, created by media design firm Local Projects and New York City–based software artist Jer Thorp. They fielded requests from victims' loved ones for "meaningful adjacencies" and received 1,200 responses. Local Projects and Thorp then went to work to build the algorithm.

Here's how it works: First, it clusters any name with adjacency requests together. If person A needs to be next to person B and person B needs to be next to person C, person A, B, and C will be grouped together. Thorp likened these clusters to "irregularly shaped puzzle pieces". The second part of the algorithm takes those puzzle pieces and fits them within the walls of the memorial. Making all the puzzle pieces fit took about a month and then tweaking the design took a bit longer.

In the end, it's an algorithm created to have an emotional impact. It gives the names on the wall a story. If you have a loved one who passed away during 9/11, you can find his or her name on the memorial here. [FastCo Design, Scientific American]