Fire broke out in the roof of an Allentown apartment building late Thursday night.
It happened around 11:30 p.m. at 2060 Vine Street in the city.
Crews at the scene said the fire was contained to the roof on one side of the building and knocked down in about 15 minutes.
Fire officials said a lighting fixture inside apartment 5 caught fire. The blaze was contained to that apartment and no other units were damaged.
Because the fire was electrical, power had to be shut off to the building.
The American Red Cross Greater Lehigh Valley assisted two families--four adults and two children--who were displaced by the fire.
The Red Cross provided lodging and food.
There were no injuries.