Police say the death of a 7-year-old Virginia girl from a severe allergic reaction at her school is a tragedy, not a crime.

Ammaria Johnson, 7, of Virginia, died Jan. 2 of cardiac arrest and anaphylaxis, according to a statement from Chesterfield County police. The girl had received a peanut from another child unaware of Ammaria's allergy, police said. Ammaria ate the peanut on the playground, and then approached a teacher, who took her to the school clinic. School personnel, responding police officers and firefighters were unable to save her life, and she was declared dead at Chippenham Hospital.

Her family says no one gave her benadryl to help treat the symptoms, and the school was told of Ammaria's allergy. Johnson's mother says she had tried to provide the school with an Epi-Pen, but had been told to keep it at home.

There is no cure for food allergies, and a person can develop them at any age. The only treatments available are antihistamines for mild reactions and injected epinephrine for anaphylaxis -- severe, life-threatening reactions in which the airway closes and the person is unable to breathe.

Most school districts have some sort of written policy on food policy management, said Maria Acebal, chief executive officer of the Food Allergy and Anaphylaxis Network. Normally, epinephrine prescribed to individual students is kept at school.