TUMBLER RIDGE, BRITISH COLUMBIA — OpenAI Chief Executive Officer Sam Altman wrote a letter on Thursday apologizing for the company's failure to alert law enforcement about the online activity of a user who later killed eight people in Tumbler Ridge, British Columbia. The letter was shared on Friday on the social media account of British Columbia Premier David Eby and on the Tumbler RidgeLines website.

"I am deeply sorry that we did not alert law enforcement to the account that was banned in June," Altman said in the letter. "While I know words can never be enough, I believe an apology is necessary to recognize the harm and irreversible loss your community has suffered."

OpenAI identified the account belonging to Jesse Van Rootselaar last June through abuse detection efforts aimed at users furthering violent activities, and banned the account that month for violating its usage policy. The company determined at the time that the activity did not meet the threshold for referral to the Royal Canadian Mounted Police.

On Feb. 10, police said, 18-year-old Van Rootselaar killed her 39-year-old mother, Jennifer Jacobs, and her 11-year-old stepbrother, Emmett Jacobs, in their northern British Columbia home. She then went to Tumbler Ridge Secondary School, where she killed five children and an educator before dying of a self-inflicted gunshot wound. Twenty-five people were injured in the attack.

In the letter, he said he had spoken with Tumbler Ridge Mayor Darryl Krakowka and Eby, who conveyed the community's anger, sadness and concern. He said it had been agreed that a public apology was necessary but that time was needed for the community to grieve.

"I want to express my deepest condolences to the entire community," he said. "No one should ever have to endure a tragedy like this. I cannot imagine anything worse in this world than losing a child." He also wrote: "Going forward, our focus will continue to be on working with all levels of government to help ensure something like this never happens again."

"It looks like OpenAI had the opportunity to prevent the mass shooting," Eby said. He said the apology was necessary but insufficient for the devastation done to the families of Tumbler Ridge. Last month, Eby said Altman had agreed to apologize to the community.