Seven adults and three children die after fire engulfs a house in eastern Pennsylvania state, officials say, with a horrified firefighter Harold Baker arriving at the site to discover charred victims were his family.

"I tried to get in as fast as I can," firefighter Harold Baker tells media, saying he attempted to enter the house multiple times before his colleagues pulled him away. (AP)

Ten people, including seven adults and three children, have been killed after a fire tore through a house and a horrified firefighter who arrived to battle the blaze only to discover that the victims were his family, authorities said.

A criminal investigation into the fire is under way, authorities said on Friday. The children who died in the fire were ages 5, 6 and 7, Pennsylvania State Police said in a news release. 

The other victims ranged in age from 19 to 79.

Nescopeck Volunteer Fire Co. firefighter Harold Baker told the Citizens' Voice newspaper of Wilkes-Barre that the 10 victims included his son, daughter, father-in-law, brother-in-law, sister-in-law, three grandchildren and two other relatives.

The fire in Nescopeck was reported around 2:30 am [local time]. One person was found dead inside the single-family home shortly after emergency responders arrived, while two other victims were found later in the morning.

Three adults escaped the blaze.

"The residence was completely destroyed by the fire" and K9 units were deployed to help in the search for victims, police said.

'They’re all dead'

Baker said that the address initially given for the call was a neighbouring home, but that he realised it was his family's residence as the fire truck approached.

"When we turned the corner up here on Dewey (Street) I knew right away what house it was just by looking down the street," Baker told the Citizens' Voice. "I was on the first engine, and when we pulled up, the whole place was fully involved. We tried to get into them."

Neighbours reported hearing a loud popping sound or explosion before seeing the front porch of the home rapidly consumed by flames. Some also reported hearing a young man screaming in front of the home, "They’re all dead."

Baker, who was relieved of his firefighting duties because of his relationship with the victims, said 14 people were living in the home. One of them was out delivering newspapers, and three others escaped, he said.

"I tried to get in as fast as I can," he told the newspaper, saying he attempted to enter multiple times before his colleagues pulled him away.

“It’s a complex criminal investigation with multiple fatalities,” Pennsylvania officials said.

Source: AFP