Kultida Woods, the Thai-born mother of Tiger Woods who instilled his dominant spirit and encouraged him to wear a red shirt on Sunday as his power color, died Tuesday.

Woods announced the death of his 78-year-old mother in a social media post. He did not disclose a cause or other details. She was at his indoor TMRW Golf League match last week in South Florida, where she lived.

He described her as a “force of nature” who was his biggest supporter from the time she drove him to junior golf tournaments in California to being there for his 15 major championships, often wearing her wide-brimmed visor and sunglasses.

“It is with heartfelt sadness that I want to share that my dear mother, Kultida Woods, passed away early this morning,” Woods wrote. “My Mom was a force of nature all her own, her spirit was simply undeniable. She was quick with the needle and a laugh. She was my biggest fan, greatest supporter, without her none of my personal achievements would have been possible. She was loved by so many, but especially by her two grandchildren, Sam and Charlie.”