Leslie Robertson at his home in New Fairfield, CT. Leslie was the lead structural engineer of the original Twin Towers and World Trade Center. Photo by Zandy Mangold Leslie Robertson at his home in New Fairfield, CT. Leslie was the lead structural engineer of the original Twin Towers and World Trade Center. Photo by Zandy Mangold Leslie Robertson at his home in New Fairfield, CT. Leslie was the lead structural engineer of the original Twin Towers and World Trade Center. Photo by Zandy Mangold Leslie Robertson at his home in New Fairfield, CT. Leslie was the lead structural engineer of the original Twin Towers and World Trade Center. Photo by Zandy Mangold