WAUKESHA, Wisc. — A 12-year-old Wisconsin girl died just hours after she went to the doctor for a sore throat, and while there, received the HPV vaccine.

Meredith Prohaska died unexpectedly on Wednesday, July 30 and her family is grasping for answers.

The cause of her death was initially listed as ‘inconclusive’. Three months after her death, the medical examiner determined the HPV vaccine did not cause her death, but instead was caused by a toxic level of an ingredient commonly found in benadryl.

FOX 4 sister station WITI spoke to Meredith’s parents. Her mother recalled the hours before Meredith was found unconscious on the floor.

That day, Rebecca Prohaska took her daughter to the doctor for a sore throat. While they were there, at about 10:30 or 11:00 a.m., Meredith got her first HPV vaccine.

Rebecca says she remembers getting a handout about possible side effects.

“Thirty minutes later she was trying to sleep. I kept waking her up,” Rebecca Prohaska said.

By 3:30 that afternoon, Rebecca Prohaska went out for a half-hour to get food.

“I came back and I found her on the floor,” Rebecca Prohaska said.

Her mother, who is a 14-year veteran Emergency Medical Technician for the National Guard, performed CPR, but Meredith was pronounced dead at the hospital. She does not agree with the medical examiner’s findings and said she wanted further investigation into Meredith’s allergies and potential reactions.

“The only thing different about that day was that shot. I wish I would’ve known more about it before I agreed to it,” Rebecca Prohaska said.

Prohaska is describes as a girl who loved to be active — swimming and playing basketball while in sixth grade at Butler Middle School.

“I’m a tough guy. I can take a beating — but this has ripped a hole in my heart,” Prohaska’s father, Mark Prohaska said.

The Prohaskas have donated Meredith’s organs and tissue so others can live a healthier life.

Click here for more pictures of Meredith and for the interview with her mother from WITI-TV. 

Click here for information from the Centers for Disease Control about the vaccine.