The 14-year-old student who shot dead two students and two teachers at his school in US' Georgia had sent an apology text to his mother before he opened fire, his grandfather told the New York Post.
The text prompted frantic calls by the mother to the school in an apparent bid to stop the tragedy, he said.
Charles Polhamus said his daughter Marcee Gray was at his house when she received a text from her son Colt Gray. "I'm sorry, mom," it read.
After she read the message, she made desperate calls to the school, trying to warn them of an "extreme emergency," her relative told The Washington Post.
"I was the one that notified the school counselor at the high school. I told them it was an extreme emergency and for them to go immediately and find [my son] to check on him," she had told her sister.
Fearing the worst, she began driving to the school and was half way there when she learned that four people had been killed, her father said.
"It's horrible. It's absolutely horrible," Marcee told The New York Post.
After receiving her panicked call, the school authorities tried to avert the disaster. A school official also went to Colt's classroom but he entered minutes after he had left the room.
Both Colt and his father are now facing charges of murder in connection to the shooting. Authorities said the father gifted him the AR-15-style rifle used in the shooting as a Christmas gift.
Featured Video Of The Day
"People Are With Me": Wrestler Vinesh Phogat Begins Campaigning For Haryana Polls
US Teen Shooter's Mother Was Arrested Regularly, Locked Him Out Of Home US School Shooting Suspect's Father Arrested. He Bought Him Gun As Christmas Gift 14-Year-Old Boy Charged With Killing Four In US School Shooting "I'm Sorry, Mom": US Teen's Text To Mother Before Shooting Dead 4 At School Trinamool MP Threatens To Quit Parliament Over Kolkata Rape-Murder Case Ajit Doval Headed To Moscow As PM Modi Tries To Broker Russia-Ukraine Peace First The Middle East, Then Europe - S Jaishankar's Key Meetings This Week 12 Die Of Pneumonitis In Gujarat, Locals Claim Fever Was Undiagnosed India's 1st Mpox Case? Centre Says Man Isolated, No Cause For Alarm Track Latest News Live on NDTV.com and get news updates from India and around the world.