Boston's bid for the 2024 Olympics is over after the mayor, Marty Walsh, says taxpayer funds will not be used to cover cost overruns.

SOUNDBITE: (English) Marty Walsh, Boston mayor

"When Boston was selected as the United States bid to host the 2024 Olympic and Paralympic Olympic Games, we celebrated as a city, as a commonwealth and as a nation. As a creative and innovative city, we saw an opportunity to reach beyond the Games and engage in a two year conversation on how to build Boston of the future, leaving a legacy for 2024, 2025, 2030 and beyond. However, even though we're only a few months into the Olympic process, I'm being asked to commit to signing the guarantee the whole city contract, language of which will not been released until September. We have always anticipated being allowed to negotiate the host city contract with the IOC (International Olympic Committee) and allow them when they decide in 2017. This is a commitment that I cannot make without assurances that Boston and it's residents will be protected. I refuse to mortgage the future of the city away. I refuse to put Boston on the hook for over-runs and I refuse to commit to signing a guarantee that uses tax payers dollars to pay for the Olympics."

SOUNDBITE: (English) Chris Dempsey, No Boston Olympics co-chairman

"This requirement for a taxpayer guarantee is something that they're (the International Olympic Committee) going to have to look at long and hard. And clearly it's smothering that Mayor (Marty) Walsh pointed to today as a potential obstacle or hurdle to moving forward. It's hard for us to see why cities should be taking on all of the risks for Olympic Games. In 1984 Los Angeles was able to host the Games without that taxpayer guarantee and we think that cities moving forward should ask for that same set of requirements."