VIDEO: 2 Young Sons of PA Deputy Killed in House Fire

Two sons of a Montgomery County, PA, sheriff's deputy were killed in a house fire in Schwenksville on Wednesday morning.

Authorities say 11-year-old Bryan Lukens Jr. and 6-year-old Parker Lukens were found dead inside the home once the flames were extinguished.

Dep. Bryan Lukens was being treated at the burn unit at Lehigh Valley Hospital. His wife, Tracy, and 9-year-old daughter Soffia were treated for their injuries at Pottstown Hospital and released, the sheriff's department said.

Witnesses say Dep. Lukens, an Iraq War veteran, made every effort to save his wife, three children, and the family dogs. “He was able to rescue his wife and daughter, but unfortunately couldn't save his two sons or the family pets," a family friend wrote on GoFundMe.

"Our office is devastated to learn about this tragedy," said Montgomery County Sheriff Sean P. Kilkenny said in a statement. "Our thoughts and prayers are with the Lukens family as they grieve their losses," WPVI TV reports.

A GoFundMe page has already raised more than $172,000 for the Lukens family.

The Pennsylvania State Police Fire Marshal determined this fire to be accidental in nature. The cause of the fire was an electrical failure of an extension cord plugged into a space heater. The origin of the fire was the porch area of the residence, CBS Philadelphia reports.