The roof caved in at the Merrimac Paper Company building in Lawrence on Monday.
Crews are working to get a massive fire under control.
Lawrence firefighters remained at the scene Saturday morning of a huge fire overnight.
Flames broke out in the house on Water Street shortly after 1 p.m. and quickly spread through the entire building.
Authorities are calling a fatal fire in Lawrence suspicious.
Firefighters battled a three-alarm fire in Lawrence on Wednesday.