It was the moment that all of Manhattan froze. Just before three in the afternoon all normal broadcasting was interrupted with a chilling bulletin: "Small plane crashes into New York building" exactly the news flash that heralded the World Trade Centre catastrophe of five years and one month ago.
The images told us that, once again, something bad had happened. And, from street level in most of Midtown Manhattan, there was no mistaking it either. From the north this time, under a leaden instead of a clear blue sky, a plume of black smoke was trailing across the city.
We are used to sirens here, but the frenzy of emergency vehicles pouring up First Avenue told anyone on the ground that another emergency had struck. "It was a 747, a 747," a middle-aged woman shouted at me from the doorstep of a chemist shop as I weaved towards the scene.
Beata Jankowska works as a housekeeper on the 33rd floor of the building that was hit, on East 72nd Street close to the East River in Manhattan.
"Everything reminds me of September 11," said Ms Jankowska, who was preparing a dinner of chicken masala when she heard an explosion and saw flames out the window below her. She raced down 33 flights of stairs to get out, taking nothing with her.
"I was very afraid," she said. "I remember September 11. I was watching that from the very first second."
Beth Schneckenburg was taking a late lunch from her job at Sotheby's, which has its new steel and glass building on the corner of the street where the plane struck. She was sitting in her favourite restaurant with friends a block away on York Avenue. Then it came. "We just heard this really loud explosion," she said. Ms Schneckenburg, in her early thirties, dashed for the door. At first, she said, she thought it must have been a car crash. But then she lifted her eyes.
"You could see things falling from the building," she said. " People were running away. Then we saw hospital employees run down the street. "
There was something else. It was a day of low cloud, but suddenly it had grown a lot darker. "Black smoke was pouring out for the building," she said.
Another New Yorker, Jill Helene, who had been on the island when the twin towers were struck, was visiting a doctor's office opposite the Belaire Condominiums when it was hit.
"I heard a terrible sound," she explained, after hurrying onto E72nd St and into a throng of emergency workers. Around her neck hung a paper face mask, of the kind worn by so many rescuers at Ground Zero.
"When I came out, the sky was completely dark and people were scattering all over the place," Ms Helene said. "I couldn't see anything on the street but there was a huge fire."