The flames broke out at 1278 St. Nicholas Avenue and 174th Street in Washignton Heights. Officials said firefighters were delayed getting to the scene because people tried to put the fire out themselves instead of just calling 911 right away.
The building houses a 99 cent store and a supermarket on the ground level, with apartments above it.
The FDNY response on St. Nicholas Avenue was massive: 40 units and 160 firefighters battling a blaze that started in a 99-cent store on the ground floor of a six-story building.
"All the smoke started rising and then people started banging on each other's doors yelling 'Fire! Fire! Fire!' So then, everyone just ran out of the building," Demetri Valles said.
Valles and his girlfriend, Rochelle Garcia, are now most concerned for their seven-month-old son.
"All his food, his clothes - everything is up there. Everything was left up there. Is it possible I could get it? I really don't know," Garcia said.
The Red Cross was working to meet the immediate needs of those displaced.
Firefighters contained the flames to the first and second floors. It was declared under control just after 12:30 p.m.
Authorities say 4 firefighters and 6 civilians suffered mostly minor injuries in the fire.