The fire broke out just before 2 a.m. Monday inside a duplex on the 300 block of Chestnut Street in Pottstown.
Pottstown Fire Chief Frank Hand said firefighters made a gallant effort to try to rescue everyone, but a partial collapse prevented them from searching the entire home for close to two hours.
"When firefighters got here, there was fire throughout the second floor and first floor in the back. They went in, made entry, but then the roof started to collapse so we had to pull our firefighters out," Chief Hand said.
Once they were able to make their way back into the home, firefighters discovered one person inside a bedroom on the second floor. The victim was pronounced dead at the scene.
Fire officials told Action News another resident had jumped from the building to escape the flames. That person was taken to Reading Hospital for treatment.
A firefighter suffered a knee injury slipping on ice while battling the blaze.
The two-alarm fire spread to a second home before firefighters were able to place it under control.
The Red Cross is assisting those who have been displaced.
The cause of the fire is under investigation.