The New York Marathon, the world’s largest, requires a massive organizational effort. Volunteers, including amateur ham radio operators, play a critical role in ensuring communication during the event. Ham radio is both a secondary method of communication if primary channels fail and a hobby that offers a range of uses. As a simple and resilient technology, ham radio is well-suited for emergency situations. In the wake of 9/11, ham radio operators proved essential in providing communication when traditional infrastructure failed. While these volunteers at the Marathon may only need to monitor inflatable donuts, their emergency backup services are ready if needed.
https://www.popsci.com/technology/ham-radio-new-york-marathon/