The flames broke out around 6 p.m. Monday in a building on Elizabeth Avenue, apparently traced to a soda machine in a first-floor dollar store.
Previous reports that the victims lived in an apartment above were incorrect, Mayor Chris Bollwage said Tuesday. Instead, he said they were shoppers in a second-floor furniture store.
The youngest victim was identified as 8-year-old Daniela Marquez, while her 10-year-old sister Paola was among those found Tuesday morning.
Their mother, Merlyn Vasquez, remains in critical condition in the intensive care unit.
A family friend, 11-year-old Elizabeth Correas, was also killed, along with another woman identified as Candida Martinez-Del Reyes, who was also found under the debris Tuesday morning.
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Rescue efforts were impeded by locked bars on a converted door and an incredible amount of smoke, and all of the victims were all found near the locked gate.
Authorities say the building is owned by Okay Roger Reality, of Brooklyn, and there are now questions about the escape route that was blocked and turned into a death trap.
"The fire and police department did a miraculous job early, but the smoke overcame them," said Bollwage, who called it a "sad day."
Officials fire was fueled by cribs and other items inside the furniture store, which proved easy tinder for the flames.
Three police officers happened to be only a block away, and Eyewitness News was told they were on the scene immediately and tried desperately to rescue a family on the second floor.
Once the fire department arrived, authorities say it was a team effort to get the victims out. It took more than 100 firefighters, 3 1/2 hours to get the scene under control.
"It was hard to control from spreading," Elizabeth Fire Director Pat Byrnes said. "We didn't see white smoke until an hour. It was constant black smoke, and we were putting lot of water on it."
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Dozens of residents were displaced, and at least one business owner is anxious to learn if her beauty salon was destroyed.
"Just waiting," Cynthia Majia said. "I don't know if I lost everything."
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