Updated Aug. 28 at 5:11 p.m. ET
A blaze that started early Sunday morning in Chicago's Mexican-American Little Village neighborhood killed 10 children, including six children under the age of 12, officials say. The other two victims were 13 and 16.
On Tuesday the Cook County Medical Examiner's office confirmed that two other victims who had been hospitalized, Cesar Contreras, 14, and Adrian Hernandez, 14, also died.
Investigators say the fire started in the back of the building in a ground-floor apartment, which was vacant.
According to the Chicago Tribune, the fire happened while two extended families were having a sleepover. The children killed ranged in age from 3 months to 16 years old.
Marcos Contreras, a relative of several of the victims, told the Chicago Tribune that his sister woke him early Sunday morning and the two ran to the site of the fire.
"By the time we got here, the whole house was on fire," he said. "They were taking out my cousins and my brothers."
Chicago fire officials said Sunday's fire was deadliest in more than a decade and that no smoke detectors were found or heard at the scene.
"It was not hard to get out," Chicago Fire Department spokesman Larry Langford told the newspaper. "The fire started in the rear, and the entryway to the front was wide open. Had they been awake or if someone had woken them, they would have gotten out."
Six of the victims were identified by the Cook County Medical Examiner's Office as 3-month-old Amayah Almaraz, 5-year-old Ariel Garcia, 10-year-old Giovanni Monarrez, 11-year-old Xavier Contreras, 13-year-old Nathan Contreras and 16-year-old Victor Mendoza. The Chicago Tribune, citing family members, identified the remaining two victims as 5-year-old Gialanni Ayala and 3-year-old Alanni Ayala. The fire department had earlier reported that some adults were among the dead.
On Monday Chicago firefighters passed out safety pamphlets to residents in Little Village and the surrounding neighborhoods.
"Every time there is a fatal fire we pass out pamphlets and smoke detectors in the community," Langford told NPR.
Officials are still investigating the cause of Sunday's fire.