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.

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.

Police say a woman stabbed three children, killing a 4-year-old boy, after she took away their phones and locked the doors to the home Friday morning in the 3600 block of West Palmer Street. The woman has been arrested,