10 World Trade Approaches Major Project Milestone: The Topping Off of Steel The Seaport's newest icon is only weeks away from reaching its full structural height at 17-stories, marking a pivotal moment for the project's vertical construction and the dynamic team behind it. The tradition of topping out has become a customary celebration whenever the skeleton of a building is complete, signifying that the uppermost steel member is going into place. The final beam is usually painted white for all project workers, designers, and stakeholders to sign. An evergreen tree or flag is raised atop the beam to represent no lives lost during the structure's assembly.