By Andrea Grymes

WAYNE, N.J. (CBSNewYork) — Three people were killed in a house fire in Wayne on Monday, and authorities are now trying to figure out exactly what happened.

Investigators spent Tuesday swarming the burned-out home on Jackson Avenue, which looks like a shell of its former self.

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There’s charred debris from the deadly fire across the front, in the back and, even worse, just steps away from a playset.

“I’m devastated. I’m so sad,” neighbor Rosemary Claeys told CBS2’s Andrea Grymes.

Claeys says her heart breaks for the kind family who lived there — a couple, their grown daughter and young granddaughter.

She says she heard an explosion around 6:15 p.m. Monday.

“Just a big explosion. Boom!” she said. “The windows to the front of the house were blown out … And the back of their house was just a wall of fire.”

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The Passaic County prosecutor’s office has released limited information but says three adults were found dead at the scene.

Claeys believes it’s the man, his daughter and the daughter’s boyfriend. She says the granddaughter was away on a trip with her grandma at the time.

Tuesday, police tape covered the property as authorities searched for answers.

“That’s who my heart breaks for, is that little girl who no longer has her mother or her grandfather,” Claeys said.

The prosecutor’s office is asking anyone with information on this fire to contact their tip line at 1-877-370-PCPO or call the Wayne Police Department at (973) 694-0600.

The exact cause of the fire is still under investigation. A PSE&G spokesperson says natural gas did not play a role in the fire.

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The names of the victims have not been officially released.

Andrea Grymes