A Larimer mother who admitted responsibility for the death of her 6-year-old son in a March house fire yesterday was sentenced to one to two years' incarceration.

Allegheny County Judge John A. Zottola imposed the sentence on Mia Marshman, 29, who pleaded guilty last month to involuntary manslaughter and endangering the welfare of children.

A city arson investigator testified at a preliminary hearing in April that Ms. Marshman appeared intoxicated and confused when rescuers spoke with her at the scene of the March 4 fire. She told investigators that she had been drinking beer and smoking marijuana with two men before she went to sleep with her 8-month-old baby, Javon Marshman. Her other two children, Isaiah, 6, and Keiyonna Trowery, 2, already had been put to bed.

After she was awakened by fire and smoke in their Winslow Street home, Ms. Marshman escaped with her baby, and firefighters rescued her daughter. Isaiah was found unresponsive in a second-floor bedroom after the fire was extinguished. He died of smoke inhalation a short time later at a hospital.

Investigators determined the fire was caused by a pot of grease left unattended on the stove. Ms. Marshman's blood alcohol level was more than three times the limit for driving.