Brooks said in a statement that he decided to coach the game because that's what he feels his mother, Lee Brooks, would have wanted.
"I appreciate the thoughts and prayers that are with my family," Brooks said. "I know my mom would want me to coach tonight's game and I do so to honor her memory and all that she meant to me as a mother and as an invaluable role model."
There was no immediate word on the cause of death.
Lee Brooks had continued operating a family-owned car wash business in Manteca, Calif. She raised Brooks and six siblings after his father left the family when Scott Brooks was still a toddler.
"Our thoughts and prayers are with Scott and his family as they mourn the loss of his mother, Lee," Thunder general manager Sam Presti said in a statement. "Over the years we have come to learn of the tremendous woman that she was; her love and dedication to family, her work ethic, her perseverance and the impact that she had on Scott. Clearly she was an incredible individual who we all came to admire in getting a small glimpse of her life. The entire Thunder organization supports Scott during this very difficult time."