According to the Centers for Disease Control, the death of an otherwise healthy 17-year-old girl only highlights the severity of this year's influenza outbreak.

Shannon Zwanziger seemed like a perfectly health teenager. She was active and rarely got sick; in fact, she had not even seen a doctor in more than three years. Then, she came down with the flu. Within only a week of fighting the virus, she was dead.

"Shortly before she died on Dec. 9, Shannon had worked her way - slowly - down the stairs at home by sitting and sliding down each step. She eventually made her way to the bathroom to take a bath" according to officials who spoke with CNN.

"I helped her get in the bathtub, but when I saw her eyes, I said, 'I think this is a mistake - we've got to get you out of here,' " her mother, Gwen, told reporters in Owatonna, Minnesota on Wednesday, Dec. 31. "She couldn't help me get her out. So I lifted her up, and she passed away in my arms." Though it wasn't until later that the doctors declared Shannon dead, she never regained consciousness.

Her mother began administering mouth-to-mouth while her husband, Terry, called 911. When Shannon arrived at the hospital she had only a slight heartbeat and was air lifted to a larger hospital. A few hours later she was gone.

Relatives said she had no health issues up till then. "Just full of life, full of fun," is how her aunt, Brenda Baska, described her for the newspaper. "She had these beautiful blue eyes. If you looked at her, you could see she had a twinkle."

While the flu is not normally fatal in teens without other underlying conditions, the H3N2 strain that is currently circulating, is associated with harsher flu seasons, and children appear to be particular susceptible. Already three children have died in Minnesota alone, and seven more children are currently being treated in the intensive care unit of the Children's Hospital in St. Paul.

Pritish Tosh, an infectious disease physician at the Mayo Clinic and a member of the Mayo vaccine research group, said this year's strain of flu is especially dangerous to children.

"The virus can enter the blood stream and then the brain, creating severe respiratory symptoms including shortness of breath and a very high fever," Tosh says. "If the body's reaction to the virus is too vigorous, this can cause as much damage as the virus itself."

According to Tosh, this flu can be dangerous to a healthy child as well, as their immune response overcompensates and overwhelms the body.

Teenagers are not normally considered a part of the groups most susceptible to the flu. In fact, the people who are most at risk are children under the age of 5, adults over 65, pregnant women and people with certain long-term health conditions. But not all cases of the influenza are the same.

According to the CDC, most people who contract the flu have mild symptoms and do not need medical care or antiviral drugs. In most cases if become ill, you should stay at home and avoid contact with other people. If you get the flu and are a part of the high risk group, or your symptoms do not improve, you should contact your health care provider.