According to police, the 4-year-old boy sustained a stab wound to the chest and was taken to an area hospital where he was pronounced dead.

A source close to the investigation said the call came into 911 from a family member, who said the children's mother "snapped" and stabbed the children before starting the fire.

A 4-year-old boy died after a woman allegedly stabbed multiple people inside a Logan Square residence before setting the home on fire Friday morning, police said.