It was unclear why Yanit Valdez, of Paterson, set fire to the building at 40 Cianci St., on Aug. 3, Passaic County Prosecutor Camelia M. Valdes, Paterson Police Chief Ibrahim Baycora, and City Fire Chief Brian McDermott said.
The blaze broke out on the upper floors of an attached three-story, wood-frame building and spread through the cockloft, blowing through the roof, shortly after 1 p.m. The fire quickly went to four alarms, with three buildings involved.
At least 20 families were displaced, said the Red Cross, which was finding them food, clothing and shelter.
Valdez was being held on various arson charges pending a first-appearance court hearing on Friday, authorities said.
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