The blaze happened around 4:30 a.m. at a home on Loyola Avenue near Dane Street. When crews arrived, they saw smoke coming from the garage.
Firefighters were able to contain the blaze quickly but not before it caused nearly $15,000 in damage.
Crews determined the cause to be a space heater which was left unattended and sparked some objects nearby.
The Red Cross is assisting the family and provided a toy for the children.