(CNN) — Marcee Gray was 200 miles away from Apalachee High School in Winder, Georgia, when her gut told her something was wrong.

It was Wednesday morning—before the school shooting that left two students and two teachers dead. She had just received a text message from her 14-year-old son, Colt Gray, saying, “I’m sorry, Mom.”

She called the school and asked the administration to check on him.

She recounted her conversation with a school counselor in an interview with ABC News. “The counselor said, ‘Well, I wanted to let you know that one of Colt’s teachers sent me an email earlier this morning saying that Colt had made references to school shootings,'” Marcee Gray said.

“I told them it was an extreme emergency and to go check on Colt right away,” Marcee Gray later said in a text message to her sister. “I don’t understand what took them so long.”

The suspect’s grandfather, Charles Polhamus, told CNN he and Marcee then drove from his home in Fitzgerald, Georgia, to Winder.

Marcee Gray told ABC News she hadn’t spoken to her son since the shooting.

“I would tell him that I love him — that me and Jesus will love him forever and ever,” she said. “And I would tell him, ‘It’s not your fault.’ It’s not his fault.”

Colt Gray now faces four counts of murder in connection with the shooting at his high school, which left two students and two adults dead.

His father, Colin Gray, 54, has been charged with four counts of involuntary manslaughter, two counts of second-degree murder and eight counts of cruelty to children, the Georgia Bureau of Investigation said. ThursdayBoth have declined to file a petition.

The surrounding community, still reeling from the tragedy, is sending its children back to school on Tuesday — with the exception of Apalachee High — as the question remains: Could more have been done to prevent the shooting?

“We know the days ahead will be difficult and that we have a number of staff and students who are not ready to return to school. We also believe as a school system that it is our responsibility to provide a safe place for those who are,” Barrow County School System Superintendent Dr. Dallas LeDuff said in a video message Sunday night.

All other schools in the district reopened Tuesday with additional security and mental health services, the district said.

Marcee Gray’s call to Apalachee High wasn’t the only warning that Wednesday morning. An unknown person called the school and said there would be shootings at five schools that day, and Apalachee would be the first, police said.

Gray left his second algebra class shortly before the shooting began, according to his classmate Lyela Sayarath, who was sitting next to him.

Shortly after, another student — who had a similar name to Gray — was taken out of class along with his backpack, Sayarath said.

When he returned to the classroom, he told Sayarath that the administrators were “looking for the boy sitting next to you, not me.”

Apalachee High School has repeatedly declined to comment on whether another student was accidentally removed from the classroom instead of Gray.

“The school failed them, that they could have prevented these deaths and they didn’t,” Lyela’s mother, Rabecca Sayarath, told The Associated Press. “I really, really feel that way.”

Barrow County Sheriff Jud Smith told CNN there were no prior warnings of a potential threat.

A spokesperson for the sheriff’s office referred questions to the Barrow County District Attorney’s Office on Monday. CNN has reached out to the district attorney’s office for additional comment.

The FBI also said it received a tip in May 2023 that Gray had threatened schools. However, agents in Jackson County, where Gray lived at the time with his father, Colin Gray, said they were unable to substantiate the tip.

When an investigator was asked at the time if Colin Gray owned an AR-15, he replied, “only shotguns.”

Colin Gray told detectives he bought the AR-style rifle used in the school shooting as a Christmas present for his son in December 2023, two police officials previously told CNN.