UVALDE, Texas (NEXSTAR) – Just two days after his wife was killed in the mass shooting at Robb Elementary School in Uvalde, Texas, Joe Garcia, the husband of teacher Irma Garcia, has died, Garcia’s relatives said Thursday.

Irma Garcia, 46, was among the 21 people killed during the attack, which happened about 85 miles west of San Antonio on Tuesday. Of these victims, 19 were students around the age of 10.

Joe Garcia’s death was first reported by the nephew of Irma Garcia, who tweeted Thursday:

“EXTREMELY heartbreaking and come with deep sorrow to say that my Tia Irma’s husband Joe Garcia has passed away due to grief, i truly am at a loss for words for how we are all feeling, PLEASE PRAY FOR OUR FAMILY, God have mercy on us, this isn’t easy.”

John Martinez, nephew of irma garcia

Martinez told NBC News Thursday that he was in disbelief after learning about Joe Garcia’s collapse at his home after delivering flowers to his wife’s memorial. Houston Chronicle explains the man reportedly suffered a heart attack.

“When he got home, he was at home for no more than three minutes after sitting down on a chair with the family. He just fell over,” Martinez told NBC News. “They tried doing chest compressions and nothing worked. The ambulance came and they couldn’t, they couldn’t bring them back.”

Irma Garcia was a fourth grade teacher and taught at Robb Elementary for 23 years.

The Garcias, who were married for 24 years, had four children. In the wake of the shooting, a GoFundMe for the Garcia family was set up, in addition to funds for families of the other victims.

A second GoFundMe – apparently also from the Garcia family – stated that Joe Garcia died Thursday morning following a “medical emergency.”

All of the student victims of Tuesday’s shooting were fourth-grade classmates of the same room, officials report.

The children’s names are: Nevaeh Bravo, Jackie Cazares, Jose Flores, Eliahna Garcia, Uziyah Garcia, Amerie Jo Garza, Xavier Javier Lopez, Annebell Rodriguez, Layla Salazar, Jailah Nicole Silguero, Jayce Luevanos, Makenna Lee Elrod, Miranda Mathis, Maite Rodriguez, Tess Marie Mata, Alithia Ramirez, Elihana Cruz Torres, Alexandria Aniyah Rubio, and Rojelio Torres.

Forty-four year-old Eva Mireles was also killed in the attack. Mireles, a wife and mother, was a fourth grade teacher and co-taught with Irma Garcia for five years. Mireles was an educator for 17 years. Both Garcia and Mireles are reported to have died while trying to shield their students from gunfire.

Irma Garcia’s nephew tweeted about the Garcias on Thursday, writing: “My Tia Irma and Joe Garcia were high school sweethearts and leave behind 4 beautiful children, their ages being 23, 19, 15 and the youngest only being 13 years old, no child should have to go through this, my heart breaks for them.”

This is a breaking story and will updated.