It was a late-summer day like any other. And then, suddenly, it wasn’t. On the tenth anniversary of September 11, 2001, eighteen photographers — some who were at home, some who were shooting other assignments in New York when the planes hit — spoke with LIFE.com about capturing history, and living to tell about it.

Kelly Guenther, then a freelance photographer for the New York Times, saw the north tower in flames from the window of her apartment in Brooklyn. She grabbed her gear and raced down to the Brooklyn Promenade along the East River, right across from lower Manhattan. “My partner told me that there was something moving in the sky. She pointed over at the Statue of Liberty and from then on, I knew what was going to happen. I trained my camera on the buildings and watched the plane come into view. I felt like it was an attack — there was just something about the way the plane was flying. Then it was just engulfed in the building. It was unbelievable. My hands were shaking because of what I’d just witnessed. Everything’s kind of fuzzy after that point.”

Guenther never completely shook the horror she felt watching that plane hit the tower. “I just wanted to shout and warn everyone, but I couldn’t do anything. I knew what was coming, and I knew that it was my job to document the moment. But the aftereffects have been hard to handle.”

Today, Guenther avoids looking at this photograph, and keeps it out of sight in her home and studio. “I feel guilty about everything associated with that image. I shoot weddings and babies now. If 9/11 didn’t happen, I’d still be a newshound. I think it just killed my spirit for news.”

Guenther is now a wedding photographer in New York City.