One person was killed in a house fire in Des Plaines early Monday morning. (WGN - Chicago)

Investigators are trying to determine if smoking in bed caused the fire in northwest suburban Des Plaines early Monday that claimed the life of 48-year-old Sandra Lupy and destroyed the home where she lived with her father, according to Fire Chief Alan Wax.

“Our firefighters did make an attack, because they knew they were looking for a victim,” said Wax. “… but realistically, conditions were such that nobody would be able to survive that.”

Relatives were still trying to comprehend the loss Monday evening.

“She loved animals, taking care of her family and cooking,” said Lupy’s younger sister, Heidi Kauke.

When firefighters arrived at the single-family, split-level home in the 1000 block of Irwin Avenue shortly after midnight, thick smoke and flames were billowing out of the doors and windows, Wax said.

Firefighters extinguished the fire within 25 minutes, but Wax said they were unable to rescue Lupy, a 1981 graduate of Maine West High School, who was on a bed in a downstairs bedroom.

The daughter of homeowner Ronald Kauke, Lupy was pronounced dead at the scene. Ronald Kauke escaped the blaze, said Wax, who added that no one else was in the home at the time of the fire. One of Lupy’s three cats died in the fire, according to Heidi Kauke.

Wax said that investigators from Des Plaines and the Illinois State Fire Marshal's office think the fire started on or around the bed where Lupy was found. He said they have ruled out an electrical problem and space heaters as possible causes, and are focusing on the possibility the fire was started by smoking in bed.

“We have not been able to definitively say that it was smoking, but we can't rule that out either,” said Wax.

Heidi Kauke said many people warned Lupy about smoking in bed.

“It's a tragedy,” the sister said. “It's your worst nightmare that you always have. It only takes one time and my sister was a heavy smoker.”

Wax said firefighters from Elk Grove Village, Elk Grove Township, Rosemont, Mount Prospect, and North Maine Township assisted.

“We extend our condolences to the family,” Wax said. “Our thoughts and prayers are with them … We know the community will come together to support them. It's just a sad thing.”

Heidi Kauke said a wake is tentatively scheduled for Friday at G.L. Hills Funeral Home, 746 Graceland Ave., Des Plaines, between 4 p.m. and 7 p.m., with a memorial to follow.

“My sister liked to laugh and have fun,” she said. “She was very kind. To me, she loved her neighborhood friends most of all.”