ST. PETERSBURG, Fla. — A St. Petersburg couple and another person escaped injury overnight as a large fired tore through their duplex. 

• Fire tears through frame
• 3 residents jumped from balcony to escape fire
• No injuries reported

St. Pete Fire Rescue officials said the fire at 950 12th Street North could have been deadly if neighbors had not woke up the residents. 

Those neighbors first spotted an orange glow outside the home around 1 a.m. and soon realized the duplex was on fire. The fire spread quickly and soon flames were shooting out of the roof. 

Three people were inside the home, one renter downstairs and a couple upstairs.

Firefighters say all three could not make it to the front door as it was blocked by fire. They ran upstairs where they had to jump off a second floor balcony.

There were no injuries reported. 

Firefighters also managed to save a dog that was trapped inside. 

The duplex was built in an old wood frame house and the fire spread dangerously fast. All that remains are the charred outside walls of the home.

The cause of the fire is unknown. Officials are investigating the fire.