Officials say the apartment building was required to have self-closing doors.

A spokesperson for the Department of Housing Preservation and Development says self-closing doors are required in all buildings with more than three units.

The spokesperson adds that it is unclear if the apartment had such door, or if something prevented it from closing when the family fled.

Flames broke out on the first floor of the building before racing through an open door and up a stairwell, killing a dozen people.

Officials say city landlords were cited more than 7,700 times in the last year for violations of the self-closing door requirement.