The fire in a warehouse in Williamsburg is still smoldering on Monday night, the FDNY said.

Units were still responding on Monday night despite that the main body of the flame had been knocked down, the FDNY said. The fire was classified as a 7-alarm blaze on Sunday.

On Sunday, people taking an afternoon stroll, walking their dog or jogging stopped to watch thick white and gray plumes of smoke billow out of a CitiStorage building —  which is packed with paper records —  at 5 N. 11th St. as a fire truck stationed on the building’s east side belted the flames with water.

Mike Kemp, a 33-year-old finance worker in Greenpoint, said he was able to smell the smoke from his apartment about five blocks away on Saturday.

“You wouldn't be able to stand right here” at the height of the fire, Kemp said from a corner near the taped-off area around the storage building. “It's the biggest fire I've ever seen.”

Williamsburg resident Chelsea Schmidt, 26, checked out the firefighting efforts while on her usual jogging route near the scene.

“It's crazy you can't even see the cityscape,” she said of the smoke that shrouded the view of the Manhattan skyline from the Williamsburg waterfront.

Schmidt, a researcher at a hospital, said friends had been sharing on social media pictures of burned pieces of medical records that now litter the patches of snow on sidewalks.

“It's not very good” for patient health information, she said.

More than 200 firefighters on Sunday were on the scene to tackle the blaze, with some crew members using fire boats on the East River. Heavy winds and the paper records stored inside the building complicated the firefighting efforts. The area around the warehouse has been cleared in case the building collapses, according to firefighter Michael Parrella, a Fire Department spokesman.

“Parts of it look unstable,” he said.

Later Sunday afternoon, an FDNY official said the fire was still classified as a seven-alarm blaze that can command up to 55 units.

Employees of nearby businesses who worked through the heavy smoke on Saturday were able to breathe a bit easier on Sunday.

Toru Nagoshi, 31, who works at Kinfolk clothing store on Wythe Avenue, said his shop closed on Saturday at 2 p.m. While walking to work, he said he was unable to see the Wythe Hotel sign across the street from his store until he was at the corner of the block.

He described the smell of the smoke as having a campfire in the middle of the store, needing to light three candles to cover the smell. On Sunday, only one candle was necessary.

“I worried about my health,” he said.

Nearby, the fire caused Kent Alehouse to lose more than half of its regular Saturday business. Nonetheless, the bar stayed open and firefighters, with ice clinging to their gear, came in to warm up, hydrate, grab coffee and eat, said bartender Garron Bible.

“Everyone was more concerned for the firefighters,” Bible said. “These guys are out here obviously putting their life on the line to put this thing out.”

(With Caroline Linton and Newsday)