Victims range in age from 5 to 79, according to authorities.
Nescopeck is approximately 95 miles northwest of Philadelphia.
According to a state police public release, officers responded to the scene of the two-story house fire shortly before 3 a.m. Friday. Three adults got out safely and 10 victims were found inside.
“Firefighters attempted to brave the rear of the home but were pushed back by the heavy flames and heat,” State Police Lt. Derek Felsman said at a news conference Friday morning.
State police identified the victims 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 7-year-old girl.
“We are deploying multiple departmental resources to ensure a thorough and comprehensive investigation into this fatal fire,” Felsman said. The home was “completely destroyed” by the fire, state police said.
When asked if authorities are conducting a criminal investigation into the fire, Felsman said “it is an arson investigation at this time.”
The cause of the fire is under investigation, Luzerne County District Attorney Sam Sanguedolce told CNN.
“If the fire department determines that the cause is intentional and arson, we would open a criminal investigation into arson,” he said.
The American Red Cross said it is responding to the needs of people displaced by the fire by providing financial support and other services, including mental health resources for victims and first responders.
“As this situation continues to unfold, we are committed to the Nescopeck community and will work with local and county officials to provide our support and programs to help those affected by this tragedy,” the Greater Pennsylvania Region of the American Red Cross told CNN. in the statement.
CNN’s Liam Reilly contributed to this report.