The victims range in age from 5 to 79 years old, according to authorities.
Nescopeck is roughly 95 miles northwest of Philadelphia.
Authorities responded to the scene of a two-story house fire a little before 3 a.m. Friday, according to a public information report from state police. Three adults made it out safely, while the 10 victims were located dead inside.
“Firefighters attempted courageous efforts to make entry into the house in the rear, but were pushed back from extensive flames and heat,” State Police Lt. Derek Felsman said in a Friday morning news conference.
The victims were identified by state police as Dale Baker, 19; Star Baker, 22; David Daubert Sr., 79; Brian Daubert, 42; Shannon Daubert, 45; Laura Daubert, 47; and Marian Slusser, 54. The three children killed were identified as two boys, ages 5 and 6, and a girl, age 7.
“We are utilizing multiple department assets to ensure a thorough and complete investigation into this fatal fire,” Felsman said. The house was “completely destroyed,” by the blaze, state police said.
When asked whether authorities were conducting a criminal investigation into the blaze, Felsman responded that “it’s a fire investigation at this time.”
The cause of the fire is under investigation, Luzerne County District Attorney Sam Sanguedolce told CNN.
“Should the fire marshals determine the cause to be intentional and incendiary, we would begin a criminal investigation for arson,” he said.
The American Red Cross said it was responding to the needs of people displaced by the fire through financial support and other services, including mental health resources for those affected and first responders.
“As this situation continues to develop, we are committed to the community of Nescopeck and will, in coordination with local and county officials, bring our support and programs to help those affected by this tragedy,” the American Red Cross Greater Pennsylvania Region told CNN in a statement.
CNN’s Liam Reilly contributed to this report.