(Ann Arbor, MI)  --  The fate of the Olympics is once again hanging in a balance.  NBC Sports Olympic host Mike Tirico says Olympians aren't going to stop their training schedules.  Tokyo 2020 President Yoshiro Mori announced the Olympics could be canceled if the coronavirus pandemic continues into next year.  Mori said the world is fighting an "invisible enemy."  He reiterated that organizers are still working towards holding the Games next year but leading Japanese doctor Yoshitake Yokokura said that it would be "difficult to hold the Olympics" without an effective vaccine.  The Games are rescheduled to start in July 2021.