Chattanooga, Tennessee (CNN) While the rest of the country gives thanks Thursday, six Chattanooga families are grieving the absence of a child from their table.

Keonte Wilson. Cor'Dayja Jones. Zyaira Mateen. D'Myunn Brown. Zoie Nash. Zyanna Harris.

All six perished after their school bus crashed and flipped over, leading to intense scrutiny over the driver's actions and safety record.

Nine-year-old Cor'Dayja Jones' family was looking forward to celebrating not just Thanksgiving with her, but also her upcoming 10th birthday on December 11.

"One of the things that I remember about Cor'Dayja was that she always smiled, and she would always give you a hug," her cousin LaFrederick Thirkill told CNN on Thursday.

But on this day of grace, both Thirkill and the family of bus driver Johnthony Walker are also heartbroken for one another.

"I pray for his family as well as I do (for) mine and the other families that were involved in this terrible accident," Thirkill said.

After Monday's crash, Walker's sister called Thirkill, the principal of a neighboring elementary school.

"She has students who attend my school as well, and so she called, very emotional and obviously grieving," Thirkill recalled.

"She just reassured me that her brother was a good person and she said that he was terribly heartbroken by the accident. She said that he was driving and he hit a curb or something and he tried to overcorrect the bus, and caused it to flip over."

Sixth child dies

Eight-year-old Keonte Wilson, who was seriously injured in the crash, "was a tough little boy" and put up a valiant fight for two days in the hospital, his brother Kevin McClendon told CNN. But on Wednesday, he became the sixth child to die.

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"I know he's in a better place," McClendon said.

More than a dozen other students were injured -- some with severe head or spinal injuries. And because some of the victims were so young, many of them didn't know their parents' names or phone numbers -- leading to massive confusion at the hospital and hours of anxiety for parents waiting to know whether their child was dead or alive.

Help from near and far

A flood of good Samaritans, ranging from the NFL's Tennessee Titans to strangers in Ohio, have rallied to help families of those killed and wounded.

The Titans will donate $25,000 to The Woodmore Fund , benefiting Woodmore Elementary School families affected by the crash.

The #Titans will donate $25,000 to The Woodmore Fund following the tragic school bus accident in Chattanooga: https://t.co/XC40fAMLaP pic.twitter.com/wSoNoqyMKp — Tennessee Titans (@Titans) November 23, 2016

The players will also wear "W.E.S." decals on their helmets when they play the Chicago Bears on Sunday.

And in Chattanooga, throngs of residents lined up for hours to donate blood to the wounded victims. Those with desperately needed O-negative blood got fast-tracked.

And amid the scramble to save victims at Children's Hospital at Erlanger, pediatric surgeon Dr. Lisa Smith said strangers have donated teddy bears, money and even pizzas ordered by people as far away as Ohio.

Bus driver crashed twice in two months

As the community mourns, investigators are trying to determine what exactly went wrong.

The fatal accident was the second time in two months that Walker crashed a school bus.

In September, Walker was driving around a blind curve in a residential area when he failed to yield the right of way and sideswiped another car, according to the accident report.

In the earlier crash, which police Sgt. Austin Garrett described as a "minor wreck," Walker "crossed over into the oncoming traffic lane to maneuver the bus through the curve and struck vehicle #2 in doing so," the report states. "There were no children in the front rows, and no reports of any injuries. The damage (was) minor to both vehicles."

Now, investigators are trying to determine why Walker, who received his commercial driver's license in April, was driving "well above" the speed limit Monday when the bus hit a mailbox, a utility pole and flipped on its side as it struck a tree.

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Garrett said no traces of alcohol or drugs were found in Walker's blood. He said investigators had obtained warrants for all data devices on the bus and were reviewing video of front, back and side views of the vehicle.

Another unanswered question: Why was the bus not on its designated route at the time of the crash?

The bus was heading down a narrow, winding road well above the speed limit of 30 mph, according to an arrest affidavit for Walker.

"Mr. Walker lost control of the bus and swerved off of the roadway to the right, striking an elevated driveway and mailbox, swerved to the left and began to overturn, striking a telephone pole and a tree," the affidavit states.

Chattanooga Police Chief Fred Fletcher told HLN the "driving was reckless and unsafe for conditions at the time."

Walker now faces five counts of vehicular homicide, as well charges of reckless endangerment and reckless driving. A sixth vehicular homicide charge likely will be added, police spokeswoman Elisa Myzal said.

Investigating the bus company

Durham School Services CEO David Duke said the company, which runs the bus service, was cooperating with the federal and local investigations.

"My responsibility now is to look for answers -- answers about why this tragedy occurred and answers for how we can make sure that this never, ever happens again," he said in a YouTube statement.

The bus company in 2007 was given a "conditional safety rating" from the Federal Motor Carrier Safety Administration. It was later upgraded to "satisfactory" after the unspecified problems were resolved, Hart said. A website lists the most recent satisfactory rating date as July 31, 2015.

"We will be exploring what were the deficiencies," Hart said.

The first lawsuit stemming from the crash was filed by the family of injured student Jamar Boling, 8. The complaint, which says Boling suffered significant physical and psychological injuries, names the driver and Durham School Services.

Grandmother of victim: 'I ain't accept it yet'

Of the six children who died, three were fourth-graders, one was a first-grader and one was a kindergartner.

Zakiyyah Mateen still can't process the death of her 6-year-old granddaughter, Zyaira Mateen.

"That was my baby," she said Wednesday. "I ain't accept it yet."

Another victim, 9-year-old Zoie Nash, was "a little angle here on earth" who was about to celebrate her 10th birthday, her uncle Antwon McClain said.

McClain remembered the fourth-grader as "a sweet, sweet girl. A little angel here on earth."

"The family is still going to have a birthday party for her in her honor," he said.

Chattanooga Mayor Andy Berke said the tragedy should remind everyone to not take their families and children for granted.

"We certainly understand on this week of Thanksgiving (that) we all need to be with our families, appreciating them, thinking about our kids," he said, "because there are a lot of families hurting in our city right now."