ROSS TOWNSHIP, Pa. -- A pregnant woman is among those who escaped from a fire Sunday morning in Ross Township.

Firefighters were called to a duplex that went up in flames at about 3 a.m. on Bellevue Road.

Two families, including a pregnant woman, were forced out of their homes as crews worked to extinguish the flames.

Firefighters said they believe the blaze began in the basement of the home.

Sam Giesey said his apartment was completely black with soot from the smoke.

"We opened our front door to our apartment and smoke came into our house," he said. "At that point, we got on the ground and got out of the house."

Giesey returned to his damaged home to salvage whatever items were left. He and his pregnant wife were asleep when the neighbors woke them up warning them to get out.

"The fire basically spread up the first floor on the duplex," said said Ross Township Fire Chief John Reubi. "On the right side, there was substantial damage in the basement and the first-floor level."

Geisey's wife was taken to a hospital as a precaution. No other injuries were reported.

The American Red Cross is assisting both families with food and clothing. For now, the Gieseys will live with family members.

The Allegheny County fire marshal is investigating the cause of the fire.