Excerpts from fox32chicago.com:

About 8:50 a.m.Saturday, someone called the Naperville Fire Department about an alarm sounding from a first-floor apartment in the first block of Olympus Drive. When fire crews arrived about five minutes later, they saw smoke pouring from the apartment and immediately entered. One person was found dead inside the apartment. The fire, which was burning in the bedroom, was put out within five minutes. No one else was inside the apartment. Investigators believe the fire was accidental, and police do not suspect any foul play.