A pre-construction survey documented cracks in the north facade of 1321 Flatbush Ave. months before the building collapsed Wednesday, as city investigators examine the property and the excavation site next door.

The March 5 survey, filed with the Department of Buildings, rated the north facade in “poor” condition. The report’s rating system defines that as a “wide range of major deficiencies noted.”

Separately, DOB says there were two enforcement actions during demolition at the neighboring construction site, 2625 Bedford Ave.

On March 20, inspectors found demolition underway without adequate overhead protection for neighboring properties. DOB issued a violation and a stop-work order.

When inspectors returned April 23, they found demolition had resumed despite the order, prompting a second violation. That violation named demolition contractor N Tech Design of America and is now listed as resolved.

DOB says the project team corrected the conditions, and the stop-work order was fully lifted May 8.

Months later, on Nov. 11, excavation was underway at the site when the neighboring building collapsed. DOB says the developers had active permits for excavation and foundation work.

The department said a three-story building had been approved for the site, while a larger nine-story proposal had not received DOB approval.

Mayor Zohran Mamdani said Thursday that the city is launching inspections at about 100 other construction sites linked to five entities involved in the Bedford Avenue project.

“If there is anyone or any entity operating in this city that bears any responsibility for what happened, we will hold them fully accountable,” Mamdani said.

DOB has issued a new full stop-work order at the construction site. The department says it is reviewing records and conditions at both properties as part of an investigation with law enforcement.

Engineering plans called for crews to monitor neighboring buildings for movement, cracks and vibration, and to stop work if certain limits were reached.

The cause of the collapse remains under investigation.