A former Tennessee school bus driver was sentenced Tuesday to four years in a crash that killed six elementary school students, according to the Chattanooga Times Free Press.

Johnthony Walker, who was 24 at the time, lost control of a bus with 37 Woodmore Elementary School students on board. He swerved, struck a telephone pole and a tree. At the time of the crash, Walker had no previous criminal history.

On March 1, a jury found Walker guilty of six counts of criminally negligent homicide in the November 2016 crash, The Atlanta Journal-Constitution previously reported.

"I just want to apologize for taking the lights out of y'all's lives,” Walker said in court Tuesday.

Judge Don Poole told the children’s parents Tennessee law prevented him from giving Walker a harsher sentence, The Times Free Press reported. Walker’s attorney requested an alternative sentencing, but Poole denied the request calling the crash “too horrific.”

Walker’s attorney said she will continue seeking an alternative sentence.