The Maricopa County Department of Public Health has confirmed the first pediatric death of the 2015-2016 flu season.
On Friday, the department said a girl was diagnosed with the H1N1 strain of influenza, which has been linked to severe illnesses in young, healthy adults.
The 2009 H1N1 strain is the main virus circulating this year, the CDC says.
At this time, it's unclear whether the child had preexisting medical conditions or where in the county she was from.
The Department of Public Health says one child died from the flu in Maricopa County last year. About 300 adults die from influenza-related complications each year in the county.