A volunteer firefighter in the US arrived to tackle a house blaze which killed seven adults and three children, only to discover the victims were his own family.

The children who died were aged five, six and seven, Pennsylvania State Police said, while the seven adults ranged from their late teens to a 79-year-old man.

Harold Baker, a volunteer firefighter in the town of Nescopeck, said the 10 victims included his son, daughter, father-in-law, brother-in-law, sister-in-law, three grandchildren and two other relatives.

Mr Baker said his two children and the other young victims were visiting their aunt and uncle’s home for swimming and other summertime fun.

Firefighters set up lights in front of a fatal house fire at 733 First Street in Nescopeck, PennsylvaniaFirefighters set up lights in front of a fatal house fire at 733 First Street in Nescopeck, Pennsylvania (Jimmy May/Bloomsburg Press Enterprise via AP)

He said 13 dogs were also in the two-storey home, but did not say if he knew whether any survived.

“All I wanted to do was go in there and get to these people, my family. That’s all that I was thinking about, getting in to them,” Mr Baker said in a phone interview with the Associated Press (AP).

Mr Baker grabbed a hose and air pack, and started pouring water on the fire, desperate to make his way inside and calling out to his son.

His chief realised whose house it was, and fellow firefighters escorted Mr Baker back to the fire station.

A preliminary investigation suggests the fire broke out on the front porch at around 2.30am local time, Luzerne County District Attorney Sam Sanguedolce said.

“The information I have is that the fire started and progressed very quickly, making it very difficult to get out,” he said.

Three people were able to escape the blaze, Mr Sanguedolce said.

Four state police fire marshals are involved in the investigation, although it will not be classified as a criminal probe unless they determine the fire was intentionally set, he said.

Crews work to demolish a house that was destroyed by a fatal fire on the 700 block of 1st Street in Nescopeck, PennsylvaniaCrews work to demolish a house that was destroyed by a fatal fire (Sean McKeag/The Citizens’ Voice via AP)

Nescopeck is a small town on the Susquehanna River, about 20 miles south-west of Wilkes-Barre.

The house was on a residential street of largely owner-occupied, single family homes.

Mr Baker said the address initially given for the call was a neighbouring house.

He realised it was his family members’ residence as the fire engine approached.

Mr Baker said his unit was the first on scene, and the house was already engulfed in flames.

“There wasn’t nothing we could’ve done to get in there. We tried, but we couldn’t get in,” said Mr Baker, 57, who has been a firefighter for 40 years.

His son, 19-year-old Dale Baker, had followed both of his parents into the fire service, joining when he was 16.

“He said it all his life, he was just going to be like his dad,” Harold Baker said.

Firefighters gather next to a home after an early morning fatal fire at 733 First Street in Nescopeck, PennsylvaniaFirefighters next to the home in Nescopeck (Jimmy May/Bloomsburg Press Enterprise via AP)

Heidi Knorr, the Nescopeck Volunteer Fire Company secretary, called Dale Baker “such a fun-loving soul. He just loved life”.

The family was “always willing to help lend a hand to anyone in need”, Ms Knorr said.

Dale’s mother was not among the dead listed by Harold Baker.

Mike Swank, who lives two doors away across the street, said he happened to be awake early on Friday and looked outside after hearing a sharp explosion.

He saw the porch “was really going” and went outside, using another neighbour’s hose to keep the blaze from spreading to a garage.

“I seen two guys outside and they were in various states of hysteria,” Mr Swank told the AP by phone.

One man was on a mobile phone “and I’m trying to ask him if everybody’s out”, he said.

“The other guy was out in the street and he was just running around in circles.”

Young people visit the site of a house that was destroyed by a fatal fire in Nescopeck, PennsylvaniaYoung people at the scene of the fatal fire (Matt Rourke/AP)

Mr Swank said he was not able to get information from them.

A fence prevented him from getting to the back of the property.

Mr Baker said 14 people were living in the home. One was out delivering newspapers, and three others escaped.

Mr Swank said the family had moved in a few months ago under what he understood to be a rent-to-own agreement, and spent a lot of time on the cluttered front porch.

“It was so quick and so much smoke, you just knew nobody was going to make it out,” Mr Swank said.

He saw cadaver dogs being used to search the scene until the bodies were located.