EMS treated two firefighters for heat exhaustion while a third sustained a minor leg injury in the three-alarm blaze, which broke out just after 11:30 a.m. on Page Avenue behind the Schuyler Diner, Police Chief James O'Connor told Daily Voice.
The source apparently was a "burn barrel," O'Connor said.
The roof of the two-and-a-half story masonry building collapsed soon after, he said.
The building was being demolished Thursday afternoon.
"There are no health hazards associated with the smoke," Lyndhurst's Office of Emergency Management said in an alert.
However, the OEM urged citizens to "keep windows closed to prevent any smoke from entering your home."No fewer than 50 responders rushed to the scene.
"There are quite a number of firefighters who gave up Thanksgiving dinner with their families to fight this fire," O'Connor told Daily Voice. "I'm very thankful for those men and women who came out on this day to protect the public."
The Bergen County Prosecutor's Arson Investigations Unit joined fire companies from several municipalities.
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