Firefighters say it may take days to fully extinguish New York City's biggest fire in a decade — apart from the 9/11 attacks — as the blaze continues to burn at a vacant warehouse along the East River waterfront in Greenpoint, Brooklyn.

The fire, which is being investigated as suspicious, started around 5:30 Tuesday morning at the site of the old Greenpoint Terminal Market at West and Noble streets.

Officials were planning to work overnight into Wednesday to combat the ongoing flare-ups.

In all, nearly 350 firefighters were called Tuesday to gain control of the enormous blaze.

The massive amount of equipment that responded on shore was supported by three Marine boats in the East River that poured millions of gallons of water on the flames, flames that quickly engulfed the warehouse in a thick blanket of black smoke.

According to the Fire Department, there is no evidence that there were any occupants inside the building at the time.

"They're warehouses and there are materials in there that are very flammable,” Fire Commissioner Nicholas Scoppetta said from the scene Tuesday afternoon. “You can see the buildings themselves are all fully involved. And there was a significant collapse during the fire as well, a lot of radiant heat from the fire, so it was a difficult fire to fight and our firefighters had to be careful how close they got."

The commissioner also said that officials wouldn't evacuate the surrounding area, but he asked that people stay away as much as possible to make it easier for the firefighters.

According to the FDNY, 14 firefighters have suffered minor injuries battling the blaze.

Smoke from the fire could be seen for miles. Rubberneckers on the FDR Drive across the East River and the nearby Long Island Expressway were given an unobstructed view during Tuesday's morning commute.

Some Greenpoint residents expressed concern about the flames spreading to what FDNY officials say is a gas storage facility a mere 1,000 feet away.

"There's a lumberyard two blocks down, there's a park across the street, there's furniture companies over here to the right of the fire — so it's a major concern now,” said one area resident. “As you can see, it's a nice, big blaze now."

"It's scary. I don't want the flames to jump to my building, so I'm a little concerned right now," added another.

The building that caught fire is a sprawling turn-of-the-century industrial park that once housed a huge rope manufacturing plant.

The current owner, Joshua Guttman, had proposed transforming the waterfront site into a residential, retail and park development, which according to architectural plans would have made use of as much of the existing structure as possible.