The Sheriff's Office identified the victims as 39-year-old Timothy Shaw, 37-year-old Melissa Shaw, 17-year-old Ethan Shaw, 15-year-old LeAnne Shaw, 12-year-old Hailey Shaw and 11-year-old Dylan Shaw, all of unincorporated Lost Nation. Officials said they all died of smoke inhalation.
Tim Shaw worked at Exelon Generation, which released a statement saying, "We are deeply saddened by this tragedy. Exelon Generation is providing grief counseling to LaSalle Station employees and our hearts go out to the Shaw family during this difficult time."
All four children were enrolled in Dixon Public Schools; two were high school students, one was in middle school and the youngest was in elementary school, the district confirmed.
"How come they couldn't escape? How come they couldn't be alive right now?" wondered Danielle Reynolds, friend of Hailey Shaw. "Why couldn't it be someone else? How come it couldn't happen today? I wish I could have said goodbye to her one last time."
Police received a 911 call just after midnight Tuesday from Ethan Shaw, who said he was trapped in the basement bedroom which was filling with smoke, according to officials. Firefighters arrived to find "a fully engulfed residential structure fire."
Capt. Isaac Demmig of the Dixon Rural Fire Department said it was impossible for firefighters to enter the house until the fire was brought under control, but when they did go inside they found that all six occupants of the residence were dead.
"This is something that no district, no community wants to endure," Ogle County Sheriff Brian VanVinkle said. "It's heartbreaking, and being around Thanksgiving it just makes it that much worse."
Ron Hinterlong, who lives two blocks away, said he heard what sounded like an explosion and then drove over to the home.
"I broke down in tears," he said. "That's it, and I don't even know them but surviving the holidays... it's going to be tough for them."
VanVinkle said authorities don't see anything suspicious about the fire and are investigating the cause along with Illinois State Fire Marshal and Illinois State Police. He said the roof of the home collapsed and there wasn't much of the residence remaining after firefighters put out the blaze.
The fire department said the bodies were found in all areas of the home, including some in their bedrooms. Ogle County Coroner Louis Finch said the bodies were so badly burned that his office will need dental records to determine identification.
First responders from 10 fire departments responded to the blaze, according to Demmig. At this point officials believe the fire started well before they received the midnight 911 call.
VanVickle described Lost Nation as a subdivision in a woodsy area with a lake in a very rural and remote part of the county. The home is about 90 miles (150 kilometers) west of downtown Chicago.
The school district has had counselors and support staff in place at all schools for students. Tuesday was the last day of school before holiday break. Support staff will be available when students return, a school official said.
"This is something that no district, no community wants to endure but Dixon is an amazing place and and I know we will all come together," said Margo Empen, superintendent of Dixon Public Schools.
The Associated Press contributed to this report.