David Epstein
Denver native Dr. David Michael Epstein passed away on July 18, 2026, at the age of 67. A service was held on July 28 at Rodef Shalom, with interment at Emanuel Cemetery. Feldman Mortuary made the arrangements.
Dr. Epstein was born on December 13, 1958. He lived in San Diego, Calif., Long Island, NY, Singapore and Belmont, Mass., before settling in Boulder.
In 1984, Dr. Epstein taught English in China, where he met his wife, Leah Ziyan Wu. They were married on August 8, 1988, in Colorado.
Dr. Epstein attended Lewis & Clark College, where he received a bachelor’s degree in chemistry. He earned a PhD in biochemistry at Brandeis University, and a post-doctoral fellowship in protein NMR at The Scripps Research Institute.
He later was chief scientific officer at OSI Pharmaceuticals and vice dean for innovation and entrepreneurship at Duke-NUS Medical School in Singapore.
Dr. Epstein was the founding president and CEO of Black Diamond Therapeutics and co-founded PairX Bio.
“Throughout his career, David led research and development efforts across the US and Asia, including China, Singapore and Japan, where his passion for science and unwavering commitment to improving patients’ lives drove the discovery and development of novel precision medicines,” his family said.
“He was a lifelong reader, traveler and foodie, creating countless memories by bringing his family around the world to explore new places, experience different cultures and share meals together.”
Survivors are Dr. Epstein’s wife, Leah Ziyan Wu; daughters Zoe Epstein and Elle Epstein; siblings Shelley (Tom) McGhee and Robert (Margot Berg) Epstein; and nieces Sydney Epstein, Emma McGhee and Ivy Epstein.
Contributions may be made to the Pan-Mass Challenge.
Bette Kal
Longtime Denver resident Bette Kal died on June 10, 2026. She was 97. A service was held on June 19 at Quebec Place at Fairmount; followed by a private interment and memorial service. Feldman Mortuary made the arrangements.
Mrs. Kal (nee Lée) was born on January 9, 1929, in Yankton, SD. She was the oldest of three siblings and moved to Denver after one year of college. In Denver she met Harold “Kelly” Kal; they were married in 1952 and were a couple before Mr. Kal’s death in 1982.
After her children were grown, Mrs. Kal worked with Mr. Kal in the flooring business, and continued to work with her son Dan until her retirement.
“Known for her elegance and impeccable sense of style, Bette always took pride in her appearance and enjoyed fashion,” her family said. “Whether attending family gatherings, social events or simply going about her day, she was invariably well-dressed, gracious and put together.
“She enjoyed listening to music, playing card games, being with relatives and friends and traveling.”
Survivors are children Sherri (Stephen) Weinstein, Dan (Kelly) Kal and Marilyn (Tim Brown) Kal-Hagan; sister Karen (Billy Kinneer) Bucher; and grandchildren Devin and Stacey Weinstein, Lesley Kal, Samantha (Justin) Hermes, Hayley Kal, Kelli (Michael) Genova and Bradley Kal Hagan.
Naomi Weitzner
Former teacher at Beth Jacob High School of Denver, Mrs. Naomi Weitzner, died in November, 2025, at the age of 86.
In 1962, Naomi married Rabbi Nachum Avigdor Weitzner. They moved to Boulder in 1965, when Rabbi Weitzner accepted the position of rabbi at CU Hillel. Mrs. Weitzner later began her teaching position in Denver.
Mrs. Weitzner was the principal of Bais Kaila of Lakewood, NJ, for 34 years.
A native of Brooklyn, NY and born in 1939, Mrs. Weitzer (née Sigfried) attended Brooklyn College, where she earned a degree in English literature. She also attended Torah Institute for Women.
After 17 years in Boulder, Rabbi Weitzner (who died in 2014 at age 75) transferred to the Hillel House at Rutgers University. Mrs. Weitzner then joined Bais Kaila in Lakewood.
“Our mother was always teaching and guiding by example,” Mrs. Weitzner’s family said. “She taught many women and set them up on a path to frum Yiddishkeit.
“She spoke at many public gatherings for women, and her signature optimism and intelligence left an indelible impression on all listeners. She wrote a weekly dvar Torah, which was distributed nationally by Torah Umesorah.
“Our mother’s contagious love of life and seeing the land of Hashem in everything infused all her lessons with a faith and trust. Our mother was a living example of a servant of G-d.”
Mrs. Weitzner’s family added:
“During her last weeks, when she was often in the hospital, the doctors realized that she was a special person. The ICU doctors were very accommodating and allowed the family unfettered access.
“She taught them about the sanctify of life, and they did what they could to preserve it.
“Our mother loved every student and went to every student’s wedding with great happiness. The trademark positivity and warmth that our mother radiated made a tremendous impression on everybody.”
© IJN 2026