Anthony Gardner had sworn off high floors of skyscrapers until his guides on a tour of New York’s 1 World Trade Center offered to take people to the 83rd story. That’s the same floor his brother, Harvey Gardner III, was on 13 years ago when the first plane hit the site’s North Tower.

“That was a sign that I needed to go up there, and I was so glad and grateful that I did,” said Gardner, 38, who left a public relations career after his brother’s death in the Sept. 11, 2001, attacks to work on behalf of victims’ families.