Columns of smoke that could be seen for miles as city firefighters battled the blaze, which they said apparently began in the retail businesses -- presumably closed because of the coronavirus pandemic – sometime after 5:30 p.m.
The three-alarm fire also severely damaged the Hackensack Riverkeeper’s offices next door.
The site was evacuated before the roof collapsed.
No injuries were immediately reported.
Records show the building was listed for sale this past January.
Joining Hackensack firefighters were their colleagues from Teaneck, Englewood, Maywood, Ridgefield Park and River Edge.
Capt. Bill Sheehan of the Hackensack Riverkeeper "is devastated, so please keep him in your thought at this terrible time," the Riverkeeper staff and "Boat" of Trustees said in a statement Sunday morning.
"The most important thing you need to know right now is this: Everyone is alright," they wrote. "No one was in the building at the time.
"The second thing you need to know is this: We ARE still on the job. Just this month we patrolled the entire river and Newark Bay from Hackensack to Staten Island, are investigating several incidents as a result, and we surveyed 40 nest sites, including three bald eagle nests. And we're planning to open our paddling centers very soon.
"And lastly, despite everything: We WILL recover from this!" the statement said. "Of that you can be sure."
"Our 'bridge crew' - staff and board - is at this very moment huddling up to plan our next maneuvers," it said. "Be sure to check our website, Facebook page and you Inbox for updates as they happen and for how you can help get us back on course."
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