The worst fire in New York in more than a decade was burning on the Brooklyn waterfront last night. The suspicious, ten-alarm blaze destroyed seven Greenpoint warehouses and involved more than 80 firefighting units, 90 trucks and other equipment, 400 firefighters from around the city, and six million gallons of water. At least 14 firefighters were treated for minor injuries; no one was killed.

Fire department officials said the fire might not be completely out until this evening.

Arson is suspected. “What we have here is a suspicious fire,” Mayor Bloomberg said, speaking at a press conference a block away from the fire shortly after the walls of one brick building collapsed. Joining Mr. Bloomberg was the fire commissioner, Nicholas Scoppetta, who said the blaze would be investigated as arson.

“The buildings were fully involved with fire when the first units arrived,” Mr. Scoppetta said. “That plus the fact that it started early in the morning are indications of a suspicious fire.”

Thick, black, acrid smoke poured into the air throughout the day. The plume was visible from Manhattan, evoking images of September 11, 2001, for neighbors who were evacuated from nearby buildings, and for motorists who observed smoke billowing up from miles away. “It reminds me of when I saw the World Trade Center collapse,” the owner of the local business Labels ‘R’ Us, Ziggy Schultz, said.

According to fire officials, the fire started inside an abandoned warehouse on the Greenpoint waterfront at about 6 a.m., affecting several three-story warehouses within a seven-building complex on West Street. By noon, Mr. Scoppetta said, the blaze was “holding but not under control.” The fire department then categorized it as an eight-alarm fire and at about 3:30 p.m. as a 10-alarm fire. Not counting the World Trade Center, the fire was the worst since a 1995 blaze destroyed Brooklyn’s St. George Hotel in a 19-alarm fire.

By comparison, the trade center disaster was so large that the fire department stopped counting alarms.

Five fire boats battled the blaze from the East River, while firefighters used several tower ladders on three side streets in a tactic called “surround and drown.”

Neighbors and workers from nearby warehouses, who were evacuated by emergency personnel yesterday morning, described the fire that sent debris and ash into the air, which was thick with smoke for several blocks near the fire more than eight hours after it broke out.

“It was just a ball of smoke and flames shooting up,” a neighbor who lives one block away on Noble Street, Boguslaw Modzlewski, said. “The flames were gushing high.”

Amid the rubble of at least four collapsed buildings, one firefighter on the scene said several commercial trucks parked nearby caught fire earlier from the blaze’s radiating heat. “That’s how hot it was,” he said. The fire department’s two tower ladders – 75 feet and 95 feet high, respectively – were being used to spray water at what was left of the smoldering buildings in the complex. “The only thing they can do now is surround it and dump water on it,” the firefighter said.

Fire officials would not speculate about what caused the fire, or whether an accelerant was used. They said the building in which the blaze began was empty at the time, al though neighbors said the building was a popular refuge for homeless people.

Longtime residents of Greenpoint, a heavily Polish area that has been the focus of waterfront redevelopment in recent years, said they suspected that the fire was deliberately set. Citing a spike in rent that he thinks is an attempt to push longtime residents out, Mr. Modzlewski said, “I think it was set on purpose. Somebody had to do that in order to build on the waterfront.”

A lifelong Greenpoint resident, Linda Schroder, 44, said, “They wouldn’t set a fire if they didn’t want the land over here.”

Speaking to reporters, Messrs. Scoppetta and Bloomberg declined to address allegations of residents being burned out of their neighborhood. “That’s not on our minds at the moment,” Mr. Bloomberg said. With the fire still burning one block away from where he stood, the mayor promised a full investigation after the blaze is extinguished. “Our first priority is getting the fire out,” he said.