Several tall units full of canned goods and other products toppled one after another, landing on customers around 3:45 p.m. Monday at Discount Outlet on Morris Avenue in the Morrisania section.
Fire officials say the collapsing shelves created a cascading effect, burying people under piles of merchandise. Responding firefighters had to remove the goods by hand and cart them onto the sidewalk.
From inside the store, Norma Villafane heard a thunderous roar.
"When I turn around, that's when I saw the other shelves come down, like a domino effect," she said. "We hear the lady screaming, and the man who was behind me, his leg was a little bit caught. I helped him get out, and he helped me come out."
It looked like a tornado tore through the building, with debris littered everywhere.
A fire department spokesman says there was no structural damage to the building.
None of the injuries, which included broken bones, are life threatening. All victims, which included two children, were taken to Lincoln Hospital in stable condition. Seven of the injuries were considered serious.
"You could hear the screaming, you could hear the lady screaming because her kids were underneath the thing, underneath all that mess," witness Lucy Tirado said. "She had two children."
More than 60 firefighters responded to the scene. The fire department says the cause of the shelving collapse is under investigation.
"Some were able to get out on their own power, but three or four had to be extricated from the debris," FDNY Deputy Chief Anthony Montera said.
To prevent a further collapse, firefighters also began removing many of the 99 cent products that had once filled the shelves, creating a large pile out on the sidewalk.
The store owners have not commented.