The fire broke out around 9 a.m. Tuesday at a residential building on Hackensack Plank Road in Weehawken.
Fire officials said the walls of the Maple Street home collapsed shortly after the fire broke out around 5:30 a.m. Thursday.
Lifelong residents said they felt like they were punched in the gut as they watched the boardwalk and numerous buildings on it get gobbled up by flames.
Firefighters made multiple attempts to go into the burning three-story building to rescue people inside but the fire was so fierce that it caused the center of the structure to collapse.
The fire started in a detached garage behind a building and then quickly spread, authorities said.
Authorities said that an intense, fast-moving fire has destroyed four homes in Perth Amboy and seriously injured three people. Dozens of people were also left homeless by the massive blaze, which started at around 4 a.m. on Sunday.
The five-alarm blaze broke out around 7:15 a.m. at Yarmouth Court and quickly spread through the roof of home, travelling along a common cockloft and damaging five other adjacent townhomes.