Excerpts from the ChicagoTribune.com:

A three-flat in the 1000 block of North Avers Avenue in Humboldt Park erupted in flames around 1:50 a.m. Saturday, killing two children and leaving a third child and three adults in critical condition. 

An 8-year-old boy, along with his 3-year-old brother, died at area hospitals. The third boy, an 18-month-old, was taken to Stroger Hospital in critical condition. Two women, 25 and 23, were also listed as critically injured at the same hospital. A 25-year-old man was in critical condition at Loyola University Medical Center in Maywood.

Firefighters arrived and began battling the blaze and rescuing those on the top floor. Investigators have not determined a cause or origin of the fire.

The boys were home with their parents and uncle when the fire broke out. All six had only recently moved into the home.