A 66-year-old great-grandmother was brutally stabbed to death in a random attack aboard a Metropolitan Atlanta Rapid Transit Authority (MARTA) train on Saturday morning.

Margaret Swan was riding the train alone around 11:20 a.m. when 25-year-old John Elijah Matthews allegedly approached her, slit her throat, and stabbed her 18 to 20 additional times, according to police and a warrant obtained by 11Alive.

Surveillance footage reportedly captured Matthews boarding the train, hovering over Swan, and carrying out the unprovoked assault. Swan screamed for help during the attack, but her daughter, Shanae Sams, said no one intervened to assist her.

“She was screaming for help, and nobody was helping her,” Sams told the New York Post.

After the stabbing, Matthews allegedly threw Swan’s body to the floor and stood over her as the train arrived at Oakland City Station. He was arrested on the platform still holding the knife after witnesses described him to MARTA police.

Matthews, who was reportedly homeless, faces a charge of felony murder. He is being held at Fulton County Jail.

Sams described her mother as the “rock of the family” — a retired parent coordinator with Atlanta Public Schools, a mother of three, grandmother of five, and great-grandmother of four.

“She was a very loving person. She would help anybody that she could. There wasn’t a bad bone in her body,” Sams said.

The family has criticized MARTA for what they call insufficient security and policing, especially during a temporary free-fare period related to system renovations. Sams believes the lack of proper security contributed to the tragedy.

“This whole situation is a situation that could have been prevented,” she said.

MARTA officials expressed condolences to Swan’s family and stated that the agency has 280 sworn officers, 30 field specialists, and 12,000 security cameras across its network. The transit authority said it is actively working to enhance security, particularly ahead of the upcoming FIFA World Cup in Atlanta.

This incident occurred less than a week after another stabbing at a different MARTA station.

The case remains under investigation.