The fire broke out at Green Hill Plaza on Parsippany Road around 12:45 a.m., according to the Parsippany Police Department.
An advanced life support ambulance was called to the scene after part of the building collapsed and a firefighter was injured, initial and unconfirmed reports said. The firefighter was later reported to be in stable condition, county officials told NJ Advance Media.
Footage from the scene shows smoke billowing out of the mall.
Meanwhile, Parsippany Road was closed between Barnsboro Road and Allentown Road and was expected to remain closed until late morning, police said.
Assisting agencies include the Fairchild Fire Company, Florham Park Fire Department, Randolph Township Fire Department 4th Battalion Ironia and Cedar Knolls Fire Department.
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