PHOTOS: Fire investigators say illegal fireworks sparked a massive fire at a Northeast Portland fourplex.
Investigators are working to see if the fire was arson and caused intentionally.
The fire was reported in the early morning hours of July 5 at the building off of Martin Luther King Jr. Boulevard along Northeast Garfield Street.
Two people were taken to the hospital -- one with critical injuries -- after firefighters say they were forced to jump from the third story.
One woman remains at Legacy Emanuel Medical Center with a fractured pelvis and shoulder.
The 10 people living at 3918 N.E. Garfield St. were displaced by the fire, which caused the building to partially collapse.