"I just lost everything I had," said Damian Woodlyn after a fire heavily damaged his Oak Street house Friday morning. 

Portsmouth firefighters extinguished the fire on Oak Street just after 9:30 a.m.

While the flames appeared out, heavy smoke was still seen flowing from the single-story house, which sits next to the Island Park playground. Police cordoned off the street around the home while firefighters continue to work. 

Updated at 10:50 a.m.

A Portsmouth police officer was the first to arrive Friday morning at 20 Oak St. 

A girl, age 13, was home alone when the fire began. The blaze is believed to have started in an air conditioning unit, but this is still under investigation. 

The girl quickly got out of the house and called 911. 

"I came out of my house on Russell Avenue and saw smoke," said Island Park resident Tom Malone. "It was a heavy, thick smoke," said fellow neighbor Tom Thayer.

"I hope she's OK," Thayer said about the 13-year-old girl. 

The homeowner, Damian Woodlyn, arrived just after 9:30. He was seen running from his black Mercedes to a Bristol Rescue to check on his daughter. 

The daughter was transported by Bristol Rescue to Hasbro Children's Hospital as a precaution. No injuries were reported. 

"At least my daughter and animals are OK," said Woodlyn later on. "I'm very stressed right now. I just lost everything I had." 

Four pets — two dogs, a cat and a blue parakeet — were inside the home at the time of the fire. The young teen managed to bring all the animals outside before the fire spread. 

Flames could be seen venting from the windows when Portsmouth firefighters first arrived. "The house was well involved in fire," said Capt. Michael O'Brien, spokesperson for the Portsmouth Fire Department. 

While the bulk of the fire was knocked down in 15 minutes, it took another 30 to 40 minutes before the remainder of the blaze was extinguished, O'Brien said. 

National Grid was called to shut off the home's electricity. Firefighters shut off the gas line to the home. 

Firefighters were also withdrawn from home due to a risk of roof collapse. "The roof was sagging," O'Brien said. "Parts of the ceiling were coming down." 

The damage to the home is extensive, according to the captain. "It's close to a complete loss," he said. 

The cause of the fire remains under investigation. 

Responding to the blaze were members of the Portsmouth Police and Fire Departments, Bristol Rescue and Tiverton Fire Department. The Little Compton fire chief was also on scene to offer assistance. 

Members of the Middletown Fire Department manned the Portsmouth fire station and later responded to the scene as mutual aid.