Shortly after 5 p.m. Saturday, a duplex at 425 W. End Ave. in Moon Township caught fire.
With the help of some neighbors, all of the occupants were able to escape from the home safely.
The fire started in one part of the duplex and then spread to the second section of the house.
The American Red Cross is assisting two families after the fire, two adults and two children from one section of the house with food and clothing, and three adults from the other with food, clothing and shelter.
The fire marshall is investigating the scene to find what caused the fire.