It all happened so fast. On Monday morning, Mayor Marty Walsh gave a defiant press conference decrying the United States Olympic Committee for trying to force his hand on a taxpayer guarantee. By that afternoon, Boston's Olympic bid was officially dead.

Since then, many observers have wondered: where did it all go wrong?

"Like in any marriage, there's no one reason for its demise," said Juliette Kayyem, former head of the security subcommittee of Boston 2024. Kayyem was not paid for her work for the committee.

Kayyem said the failure of the bid could not be pinpointed to one factor in particular, citing a number of issues including the committee's trouble communicating a vision for the Games to the city and a general lack of support from the public.

"People are focusing on, 'oh, Boston 2024 did this' or 'oh, the USOC did that' or 'so and so said this,'" she said. "I think it was cumulative. It fundamentally came down to: there was not support for the Olympics by enough people for the USOC to feel comfortable," she said.

Kayyem said, in the end, she was disappointed and called the failed bid a "missed opportunity" for Boston.

"There were heartfelt people who believed this was the wrong city at the wrong time. There are heartfelt people who aren't in it for the money who aren't naive, who believed it was the right city at the right time," she said.

"I don't think I was on the wrong side," Kayyem continued. "I think I was just on the losing side."

To hear more from Juliette Kayyem, tune in to Boston Public Radio above.