An adult and children have died after a Wednesday morning house fire on the Oneida Nation of the Thames First Nation, sources close to the investigation have confirmed to CBC News.

The fire engulfed a single residence shortly after 11 a.m. on the 1200 block of Townline Road. The damage estimate and cause of the fire is currently unknown.

The ages and number of family members involved weren't yet clear.

The family often frequented the nearby convenience store and gas station. Joseph Ireland has worked at Ambrose Gas Bar & Convenience for a month and said he would see the children come in in groups of two or three to buy snacks and sometimes gas for their parents.

"It's funny because they were really little and they'd have to reach over the counter so sometimes they would say this in gas please," Ireland said. "They were very polite. Very wonderful children."

He believes the mother went out to St. Thomas, Ont., to pick up Christmas care for their family at the Salvation Army. Ireland said some of the children were at school, some stayed at home because they were sick. He's heartbroken this happened.

"This is a time when people are supposed to be getting together, not be torn apart by something like this."

The fire marshal will investigate the blaze.