Joe Dittmar was on the 105th floor of the World Trade Center’s South Tower on Sept. 11, 2001. He recounts what happened that morning in a StoryCorps interview last year in Chapel Hill, N.C.

Joe Dittmar was on the 105th floor of the World Trade Center's South Tower on Sept. 11, 2001. He recounts what happened that morning in a StoryCorps interview last year in Chapel Hill, N.C.

Joe Dittmar was on the 105th floor of the World Trade Center’s South Tower on Sept. 11, 2001. He recounts what happened that morning in a StoryCorps interview last year in Chapel Hill, N.C.

Joe Dittmar was on the 105th floor of the World Trade Center’s South Tower on Sept. 11, 2001. He recounts what happened that morning in a StoryCorps interview last year in Chapel Hill, N.C.