The blaze at 601 Beachway was reported before 1:30 a.m. Monday.
The heat was so intense it melted the siding of houses across the street.
"I came around the corner, and I saw the flames 60 feet in the air. I mean, I've never seen a fire like that before," said Vince Mondano.
Mondano's home is across the street from the 16 unit vacant condominium complex. The construction on the complex had recently come to a stop.
The wind blew the flames as they destroyed five condos across the street, and even damaged an apartment house down the block
"It destroyed four cars across the street," said Michael Pigott with Keansburg Police Department.
Police cleared out every resident and there were no injuries.
Now investigators need to determine what led to the fire and all this destruction.
Firefighters are still pouring water on some areas of the rubble, trying to put out pockets of fire. Once they are is safe, Fire Marshals will investigate and try to figure out what started this fire.