Fire officials in Reading say the blaze broke out around 3:45 a.m. Wednesday in a four-story apartment building with between 10 and 15 units.
The fire went to three alarms and it took firefighters nearly three hours to bring the flames under control.
Eddie Rosado, who lives in a nearby building, described the scene.
"The entire 4th floor was engulfed in flames and smoke. It was spectacular and frightening. I immediately began praying for the people inside," he said.
One of the two injured was a woman who lives on the fourth floor. Witnesses say that woman tried to put the fire out herself, though that has not yet been confirmed by investigators. If that is the case, Reading Fire Marshal Todd Iaeger said all she was doing was putting her life in danger.
"Always, always - if you have a fire, evacuate. Get everyone out, evacuate and call 911," Iager said.
That woman was flown to the burn unit at Lehigh Valley Hospital.
A fire company lieutenant was taken to a hospital for treatment of first-degree burns on his shoulder. He has since been released.
Approximately two dozen people were left homeless by this fire and are being cared by for the Red Cross at the local YMCA.