Fire crews in Berks County were called to the former Argo Furniture Co. warehouse in Reading just after 7:30 p.m. Saturday.
Officials say the four-story, 51,000-square-foot building was engulfed in flames within minutes, sending flames high into the night sky and dark smoke billowing across much of the city.
Dozens of firefighters from the city and surrounding municipalities battled the flames late into the night. They reported at about 10 p.m. that part of the building had collapsed.
The Berks County chapter of the American Red Cross said assistance was being provided to several families.
Authorities said the cause of the fire was still under investigation.