The fire started shortly after midnight on New Year's Day and burned for more than 2 hours in the city's Bustleton section along Bustleton Avenue between Benson and Hoffnagle.
A 70-year-old woman was killed in the blaze.
On Friday, police say the fire was sparked by Christmas lights.
Medics took seven other victims to Temple for burns and other injuries.
The fire hit at least several units on the top floor of the 3-story apartment building, gutting some of them.
Fire Commissioner Lloyd Ayers says the building had a properly working smoke alarm system that did function.
However, Ayers said his chief concern was that some of the residents heard the alarm, but failed to evacuate timely, resulting in rescues being necessary.
