The fire broke out at 420 Lincoln Ave., a known abandoned building, just before 9 p.m.
The fire extended through the whole house, gutting it, then spread to an adjacent home.
At least two families were living in that home; 10 people were left homeless by the fire.
There was a partial collapse of the building where the fire started.
One person, believed to be a man who was squatting in the abandoned building, was killed in the fire. The injured firefighter is stable.
Neighbors have complained about squatters in the building.
People living in the area were advised to close their window to avoid smoke exposure. It took about two hours to bring the fire under control.