She stayed in her bedroom for days, unable to come out. No one let her see her mother's body to say goodbye, thinking it was better for her daughter to remember how she was alive.
"I pretty much almost dropped out of high school," said Thomas, who was a sophomore when her mother, Social Security Administration employee Charlotte Thomas, died in the April 19, 1995, attack.
Thomas limped to graduation with no idea what her future held. But 15 years later, she is a college graduate working toward an advanced degree in speech pathology at Howard University in Washington, D.C., all because of a fund that ensured her tuition would be covered because of the loss she suffered as a child.
More than 200 children had parents killed or disabled when an anti-government conspirator's truck bomb destroyed the Alfred P. Murrah Federal Building. Thomas and others have benefited from a continuing legacy of the attack: the outpouring of donations from people who wanted to help the families of the victims.
At the time of the blast, the children ranged from infants to teenagers. Suddenly, they were left to be raised by single parents or grandparents, were placed with other family members or sent to homes in other states.
With the scholarship money available, about two-thirds have since gone on to college or other education programs, and the graduates now include physicians, lawyers, veterinarians and pharmacists.
"It was not about distributing money," said Nancy B. Anthony, executive director of the Oklahoma City Community Foundation, which administers the fund created from the donations. "It was about how to help people restore their lives."
She said the fund has spent about $6 million on tuition, housing and other educational costs. It has also paid for counseling for depression and emotional problems.
As the bombing shattered the lives of the victims' families, the donations changed the future for many of the children.
"Going to college would have been difficult," said Marisa Williams, 28, who obtained a public relations degree at Oklahoma State University after her father, Jules Valdez, who worked for the Department of Housing and Urban Development, was killed. "My parents had done a great job in saving, but it wouldn't have covered everything."
Dr. Kyle Loudenslager, who lost his father, General Services Administration employee Michael Loudenslager, said he likely would not have pursued his veterinary medicine degree at OSU were it not for the scholarship help.
"It's not that I couldn't have done it. It's just that I wouldn't have done it," said Loudenslager, 37, who practices at the Deercreek Animal Hospital in Harrah, Okla. "They gave me the opportunity to do what I wanted to do."
Years after the attack, volunteers and case workers still checked in periodically with families, asking how the children were doing and suggesting answers for problems.
At the time her mother was killed, Dion Thomas, the youngest of three children, was a shy tomboy who liked math and science and did well in advanced placement classes. The children "were raised with love. They were the sweetest kids," said Bettie Lewis, Thomas' grandmother. "They were no problem at all - until their lives just changed."
Since the children's father was not always present, Lewis cared for the children after Charlotte Thomas' death. But Dion couldn't find her bearings. After graduation from Northwest Classen High School in 1997, she drifted between menial fast-food jobs before trying college, then quickly dropping out. "I still was not in the right mindset," she said.
Finally, she enlisted in the Army and found a purpose. The breakthrough came while she was serving at Walter Reed Army Medical Center in Washington, when she befriended a speech pathologist who was helping war veterans with brain injuries learn to speak again.
Thomas settled on speech pathology as a career. The money donated after the bombing attack helped pay for the schooling. "I am so thankful for the opportunity that they gave me. I don't know what I would be doing," Thomas said. She said that after she finishes her master's degree in a year, she may pursue a doctorate.
Those who remember her from high school are amazed by the turnabout in her life. "To see Dion go through what she did, I wouldn't have expected it," said Denise Miller, a librarian at Northwest Classen. "She had a real hard time."
Thomas' older brothers have not fared as well. One brother, John Cornelius Thomas, was released on parole last year after serving 12 years in state prison for attempted robbery. The other, Adrion Thomas, was sentenced to five years following an August conviction for possession of a controlled dangerous substance.
Lewis said Dion Thomas' academic success would make her mother proud.
"Out of evil, there is some good," Miller said. "And she found the good."