Firefighters responded to 3rd Avenue near East 183rd Street in Belmont just after 12:20 p.m. for reports of a person injured.
They carried out a technical rescue to extricate the man who fell approximately 12-15 feet down a hole in the sidewalk.
He was treated at the scene and taken to St. Barnabas Hospital in serious, but stable condition.
Department of Buildings inspectors said a sidewalk vault that was in a state of disrepair is what collapsed.
Because of this, they issued a full vacate order for the building.
The building owner was ordered to immediately install a construction fence at the property to protect the public.
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