Pittsburgh Fire, EMS and Police responded to the 500 block of Griffin Street, for a reported fire around 1 p.m.
When Firefighters arrived, they observed smoke and flames in the lower part of a row house.
The residents were not home at the time of the fire.
Firefighters did discover three pets. Two cats in one home, and a dog in another. The pets did not survive.
The fire was raised to 3-alarms due to heat related weather. There were no other injuries.
The Fire Investigation Unit are looking into the cause.