By Marissa Parra

CHICAGO (CBS) — A huge fire destroys a building in west suburban Cicero.

Now firefighters are trying to find out what sparked the blaze. A five-year-old boy and his grandfather did not survive.

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CBS 2’s Marissa Parra spent the day at the scene as investigators looked for answer.

Overnight, the flames inside a Cicero home claimed two lives and almost everything inside.

The house now stands hollowed and charred.

It was once the loving home to the Castellanos family, including grandfather, David Castellanos and his five-year-old grandson, who the family called “Little Junior” — neither of them made it out.

A man who used to work with the grandfather told us in Spanish the Castellanos are a close and loving family calling them “good people” and saying “we all loved each other.”

The fire engulfed the house in the quiet of the night. Firefighters said that efforts to contain the fire were hindered by strong winds.

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Even with all their protective gear, they couldn’t get inside right away to help. Those flames, spanning the entire back of the building, from top to bottom, even sending a firefighter to the hospital.

Once inside, firefighters found five-year-old boy alive, but attempts to save him failed.

His grandfather, already lost to smoke inhalation.

“You never want to have these kinds of fires. You know you don’t want to have any fires but when you got fatalities and it involves a child, it hits home with the guys. It hits home with all of us,” said Cicero Fire Chief Dominick Buscemi.

Now, remnants of happier times lay still and unused in the yard. In the shadow of the overnight disaster, in the home of a family that will never be the same.

The family said there were other family members inside who were able to make it out safely.

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A GoFundMe site has been set up to help the family with funeral costs.