An 11-year-old who survived the Texas school shooting was hospitalized after she suffered cardiac arrest while visiting her best friend's memorial.

IIliana Treviño lost her best friend, Amerie Jo Garza, on May 24, during a mass shooting at Robb Elementary School in Uvalde, Texas.

While visiting Amerie's memorial to place flowers and a teddy bear, IIliana's heart rate spiked, and she had to be rushed to the hospital, where doctors said she was on the verge of having a heart attack.

According to IIliana's mother, Jessica Treviño, IIliana's best friend Amerie would protect her daughter from school bullies.

Jessica, shared on a GoFundMe page to raise funds for medical bills:

"Amerie would protect Illiana from bullies and always came to her aid. Her heart can't take the stress and trauma of this past week."

She added:

"We are barely seeing the ripple side effects of what this tragic incident has brought to our community."

The mom also revealed on the GoFundMe page that the medication that her daughter was given wasn't working.

She added that doctors told her Illiana was showing symptoms of post-traumatic stress disorder and acute stress from the trauma she experienced. Thus, if immediate action isn't taken, Illiana might suffer cardiac arrests again.

Jessica said:

"Her body was basically shutting down completely. It couldn't take it. Her body was reacting to the shock."

Speaking to People, Jessica said her 11-year-old daughter had never experienced heart issues before the incident.

She told the outlet:

"I think it's just from a broken heart that we need to work on healing."

"Everything just broke her in half, and she feels the fear of being bullied again."

While Illiana survived the massacre, which took the lives of 19 of her classmates and her two teachers, Amerie was fatally shot while trying to dial 911 from her phone.

When the fourth grade saw her best friend's face on the news, confirming her death, "she just started screaming and crying," and they tried to comfort her.

According to the mother, Illiana is now terrified to go back to school on her own.

She said:

"Amerie made her feel safe and made her feel okay to go to school."

Paying a heartfelt tribute to her daughter's best friend, Jessica added:

"Amerie's parents did an amazing job raising such a beautiful little love. It's so sad how things work out in life because it's not fair. It really isn't fair that any of these children lost their lives, but it just really breaks me more because I know how much this child did for my child."

Illiana's story is similar to that of the husband of one of the two teachers killed in the shooting who died of a heart attack.

Irma Garcia, 46, was one of two teachers killed by the gunman.

Two days later, on May 26, her grief-stricken husband Joe died of a heart attack.

Irma's cousin Debra Austin said:

"I truly believe Joe died of a broken heart and losing the love of his life of more than 30 years was too much to bear."

Amerie Jo Garza was laid to rest on May 31 at Sacred Heart Catholic Church, a 114-year-old church about a mile from the elementary school where she was murdered.

Amerie's stepdad, Angel Garza, a medic, rushed to the school on hearing the news of the shooting.

He said:

"I just want people to know she died trying to save her classmates,' her stepfather said.

"She just wanted to save everyone."

Due to her heroism, Amerie was posthumously awarded the Bronze Cross by the Girl Scouts of the United States of America.

The national award is reserved for Girl Scouts who show 'extraordinary heroism' or risk their lives to save another's.

Her family said:

"Amerie Jo Garza was a kind, caring, blunt, loving, sweet, sassy and of course funny little diva who 'hated dresses' but; she truly had a heart of gold."

The day after her death, her mother, Kimberly Garcia, posted a picture of Amerie holding up a certificate in recognition of joining the A-B honor roll.

Other children and teachers who died in the Robb Elementary School shooting are:

Uziyah Garcia, 8

Makenna Elrod, 10

Xavier Lopez, 10

Eliahana Torres, 10

Ellie Lugo, 10

Nevaeh Bravo, 10

Tess Marie Mata (her age couldn't be confirmed)

Rojelio Torres, 10

Jayce Carmelo Luevanos, 10

Jailah Nicole Silguero, 10

Alithia Ramirez, 10

Annabell Guadalupe Rodriguez, 10

Miranda Mathis, 11

Alexandria 'Lexi' Aniyah Rubio, 10

Maite Yuleana (her age couldn't be confirmed)

Jose Flores Jr, 10

Jackie Cazares, 10

Layla Salazar, 10

Irma Garcia, 46 (a fourth-grade teacher)

Eva Mireles, 44 (a fourth-grade teacher)