It is with deep sadness that we announce the peaceful passing of Sonia Heasook Kim (née Yoon) on July 17, 2026, in Fairfax, Virginia, with her husband by her side.

Yoon Hea Sook was born in Iri (now known as Iksan), South Korea, on September 17, 1949, to Yoon Boo Byung and Yang Jong Shin. She was the second daughter of five children, with two older brothers (one who passed before Hea Sook was born), one older sister, and one younger sister.

Hea Sook spent most of her childhood and adolescence with her sisters and brother in Seoul. She attended college in Seoul for art—and though she never pursued an art career, her artistic sense was evident in everything she did—from cooking to clothing to home decorating.

In 1972, she married her husband of 54 years, Dr. Poong Young Kim, whom she had met while he was in medical school in Seoul. The couple lived in Japan until 1980, where Dr. Kim had grown up, before emigrating to Chicago, Illinois, with their two daughters, both born in Osaka, Japan in 1975 and 1979. In 1981, they welcomed their third daughter, born in Evanston, Illinois.

The family moved to Houston, Texas in 1983, where Hea Sook spent nearly 40 years actively supporting her husband’s medical practice, enjoying time with her older brother, two sisters, and their families, and participating deeply in the local Korean immigrant community and church life. In 1995, Hea Sook and Poong Young became US citizens and changed their names to Sonia and Paul respectively. In their final years in Houston, Sonia and Paul both served as elders at Hilltop Lutheran Korean Church. Three years after Dr. Kim's retirement in 2019, they moved to Springfield, Virginia, to be closer to their beloved grandsons.

Sonia loved art, food, fashion, and dogs—especially her Boston Terrier, Chul-Soo.  We will dearly miss her style, elegance, and irreverence. Her faith was quiet and true, like her personality, and she endured with a positive attitude up until the end of her life.

In the United States, Sonia is survived by her husband, Dr. Paul Poongyoung Kim; her three daughters, Lana Ahrim Trzcinski, Chaerim Kim Smith, and Naerim Kim Geddes; her sons-in-law, Todd Moore Trzcinski and Derek Daniel Paul Smith; her grandsons, Oscar Loren Smith and Felix Young Smith; her sisters, Yoon In Sook and Yoon Hea Kyung; her brothers-in-law, Chang Tai C and Kang Sung Soo; and her nieces, Jennie Leigh Cardoza, Christine Yoon Lee, and Erin Yoon Kang.  In Japan, she is survived by two sisters-in-law, two brothers-in-law, and their families, including multiple nieces, nephews, and their children.

She is preceded in death by her parents; her two brothers, Yoon Young Gil and Yoon Kwang Il; and her son-in-law, Brian David Geddes.

Sonia will be laid to rest beside her parents at Norbeck Memorial Park in Olney, Maryland, in a private ceremony.