28-Year-Old San Francisco Man Stabbed to Death Trying to Protect a Mother and Her Two Kids — Details of the 'Utterly Unprovoked' Attack

In the moments before his death, Colden Kimber quietly moved to stand between a stranger and a frightened family — unaware that his final act of courage would soon spark an outpouring of grief, a criminal investigation, and a community rallying to preserve his memory.

A 28-year-old San Francisco man was fatally stabbed while trying to protect a woman and her two children from a stranger's verbal aggression, according to court documents released this week.

The victim, identified as Colden Kimber, was a cyclist and hockey player studying kinesiology at San Francisco State University. The incident took place on Saturday, July 26, 2025, as Colden and his girlfriend were heading home, waiting for the "K" train on Ocean Avenue after lunch.

Court documents state that Colden noticed a man yelling at a mother and her children, saying things like "Oh, you think you are better than me," and "You are scared of me."

He then moved to stand between the man and the family. The document explained that he "decided to position himself... so should anything happen, [he] could intervene and protect those around him."

While Colden faced the approaching train, the man suddenly attacked him. Despite medical aid from first responders and trauma surgeons, he did not survive.

The court described the event as "completely and utterly unprovoked — took a knife and stabbed the unsuspecting victim on the right side of his neck."

Friends and coworkers have expressed deep shock and grief over Colden's death. "It was so horrendous and shocking and the last person that I would expect something like that to happen to," said Reuben Sawyer, a friend of Colden's.

Bradley Woehl, owner of American Cyclery where Colden worked, recalled his impact. "I'm going to miss him for his good nature and his kind spirit... He was a very positive influence on myself and my staff."

Colden had worked there for three years. "This up here was his work bench that he repaired bikes and built new bikes," Bradley mentioned. The bench now sits empty.

"[Colden] is totally irreplaceable as a worker, and totally irreplaceable as a friend and person and someone who had a good influence in my life," he added.

The San Francisco District Attorney's Office confirmed that the suspect, identified in court documents as 29-year-old Sean Collins, has been charged with murder. His arraignment is scheduled for August 14.

San Francisco Supervisor Chyanne Chen, who oversees the Taraval District where the incident occurred, stated, "Still under investigation. So, I'm following very closely with the San Francisco Police Department, SFMTA."

A report regarding Sean's mental health status was filed on Friday (August 1), but the results remain pending. As authorities continue their investigation, those who knew Colden are left searching for answers. "We love him, and we miss him," Bradley expressed.

A memorial ride honoring Colden is scheduled for September 7 around the Polo Fields in Golden Gate Park. The event is one of several efforts by his family and community to commemorate his life following the fatal attack in San Francisco on July 26.

Colden's family has also launched a GoFundMe campaign, organized by his mother, Lara Litchfield-Kimber. The fundraiser aims to support memorial services in both San Francisco and New York, as well as help the family manage legal proceedings.

As of now, the fundraiser has raised over $109,000 toward its $120,000 goal. More donations are expected to pour in soon.

Lara shared that her son's actions that day were consistent with the person he had always been. "He would definitely do that without hesitation," she told The San Francisco Standard. "That does square with everything I know about him. He was a very protective big brother, and he was very protective of me."

According to her, Colden had been in contact with his 23-year-old sister moments before the attack. "I'm very proud of the person he grew into," she added.

In a Facebook post, Lara thanked those who had reached out in recent days. She also shared the fundraiser link and explained that the financial help would assist with memorial events and the legal process unfolding far from where the family resides.

Lara has also changed her Facebook cover photo to an image of Mount Colden in the Adirondacks. In a reflective post, she mentioned that the mountain, one of Colden's favorites, had been damaged by a rock and mudslide just nine days before his death.

Additionally, Colden's friends have shared tributes online. One friend, Lorie Walker, expressed grief over his sudden death. "There in no making sense of this, and no words to convey the devastation. We will all miss you Colden," she wrote on Facebook.

Colden's cycling team, Dolce Vita Cycling, shared a touching message on Instagram, honoring his courage and kindness. The group remembered him as a teammate and friend who died protecting others.

They described the amateur cycling world as often self-focused but said Colden stood out for his generosity and kindness.

He was known for mentoring mechanics, coaching racers, teaching new riders, and helping others with their bikes. The cycling community recalled him as a bright presence whose impact would be long-lasting.

Colden is remembered for his selflessness, strength, and the positive mark he left on those who knew him. As loved ones prepare to honor his life, the outpouring of tributes reflects a legacy defined by compassion and courage.