The Cook County Medical Examiner's office identified the three women as Doris Miller, 93, Tetiana Krych, 62, and Svitlana Kandelis, 40. Miller and Krych lived in the home on Dunton, while Kandelis lived in Wheeling.
Investigators have not officially determined how and where the fire started, but the worst of the damage appears to be in the back of the house where part of the second floor collapsed.
On Wednesday night, the work of board-up crews capped a day of sadness at the two-story house.
"Count your blessings. Tragic things happen to people all the time, and it's hard to witness it," said Cheryl Brown, neighbor.
The Arlington Heights Fire Department set up a command post at the scene in the 300-block of South Dunton. There was no call to 911, instead, a police officer blocks away happened to smell the smoke.
"It was incredible. Flames shooting out of the back of the house top and bottom floor so it was obviously at the peak when I woke up. Just incredible flames," Barry Carlson, who lives nearby, said.
As flames consumed the upper floor, next door resident Jung-Fu Huang feared for his neighbors.
"When I wake up, I stepped outside and hoped they are alright. But obviously the front door is still locked," said Huang.
Authorities say the oldest victim, Miller, was pulled from a first floor bedroom but died at the scene. The other two female victims were found after the fire was out near the first-floor entrance. It appeared they had tried to escape.
Neighbors say Miller was a longtime resident of the block and one of the other victims was likely her live-in caregiver.
"The caregiver was pretty nice. She planted tomatoes and some food, and she would always give to me," said Huang.
Fortunately, the fire did not spread to any neighboring homes. Officials say as firefighters arrived, they did not hear the sound of smoke alarms. Whether alarms were present in the home is being investigated.