The head coach of American football team Buffalo Bills has apologised for using the September 11 hijackers as an example of teamwork during a talk with his players.
Sean McDermott said he regretted making the reference at a training camp session in 2019 and that he "immediately" said sorry to his team following the incident.
McDermott "cited the hijackers as a group of people who were all able to get on the same page to orchestrate attacks to perfection," according to a report by US journalist and blogger Tyler Dunne.
He then reportedly quizzed his players about what obstacles the attackers had faced, as well as asking them: "What tactics do you think they used to come together?"
Players were said to be stunned by the "strange" comments, with one member of the team left "horrified", Dunne said.
Nearly 3,000 people died during the September 11 attacks in 2001, when 19 men hijacked four passenger planes before crashing them into targets including the World Trade Center in New York.
The attempt to steer the fourth plane into a high-profile target, possibly the White House, failed when passengers staged a rebellion, causing the aircraft to crash in a field in Pennsylvania instead.
At a press conference on Thursday, McDermott appeared to admit he made the comments and acknowledged he "didn't do a good enough job of communicating clearly the intent of my message".
He told reporters: "My intent in the meeting that day was to discuss the importance of communication and being on the same page with the team.
"I regretted mentioning 9/11 in my message that day, and I immediately apologised to the team.
"Not only was 9/11 a horrific event in our country's history, but a day that I lost a good family friend."
He added: "If anyone misinterpreted or didn't understand my message, I apologise.
"That was about the importance of communication and that everyone needs to be on the same page, ironically enough. So that was important to me then and still is now."
The revelation about his comments came in a lengthy series of blog posts by Dunne about the Buffalo Bills and their alleged McDermott "problem".
The 49-year-old is in his seventh season in charge of the NFL team and had previously won praise for turning around their fortunes.
But he has come under scrutiny in recent months following claims from fans and pundits that the side has underachieved this year.
Dunne said he had spoken to multiple anonymous players and sources at the Buffalo Bills, with one claiming the coach was "awkward" and lacking in social skills.
McDermott also allegedly perplexed players during a team talk when he discussed the attempted rescue of a woman who died after driving into the river by Niagara Falls in December 2021.
"The coach explained how members from the coast guard did everything they could to save the woman. He built up the drama. Players held on tight for an inspiring apex, and... nothing. He said the woman died. End of story," wrote Dunne.
McDermott told the press conference he did not want to comment on other alleged issues raised in Dunne's article.