A 13-year-old Georgia girl, Julia Chavez who went to the emergency room with a headache died from undiagnosed leukemia less than 12 hours later.

Julia Chavez was a student at Harlem Middle School in Columbia County. According to the Augusta Chronicle, she had an ear infection and headache over the weekend and was prescribed antibiotics at a local urgent care.

The teen collapsed on Sunday and was taken to the hospital in Augusta, where CT scans and bloodwork revealed she had leukemia.

“She had bleeding in her brain, lungs, stomach… everywhere,” her father, Dennis Lee Chavez, wrote on social media. “That’s where we found out she had leukemia. It came on so hard and so fast. Doctors told us there was no way we could have known.”

Chavez died at 1:35 a.m. Monday, just hours after she was admitted.

Family members told the Chronicle that the only symptom she had was occasional bruising, but they chalked that up to her being somewhat of a tomboy.

Her teacher, Caroline Pinkston, said her 5th-period classroom isn’t the same.

“Julia was the kindest, most big-hearted child I think I’ve ever met; even her speaking voice was sweet. She would talk to anyone and make them feel friended,” Pinkston wrote.

Julia will be buried in Grovetown on Friday.