Halifax Regional Police said someone called 911 from a payphone at the corner of Spring Garden Road and South Park Street and made threats that alluded to the Boston Marathon bombing.
Nearby, nearly 700 people were gathered at the Oval in the Halifax Common for the Relay for Life.
Police met with the organizers and the fundraiser was called off, ruining a year’s worth of work by dozens of volunteers.
“I would say don't ever do this again because you are hurting people in their time of need,” said Barbra Stead-Coyle, CEO of the Cancer Society.
“Last night my heart broke for the volunteers who put their whole heart and soul into making last night’s events.”
A day later the safety concerns were at the top of organizers’ minds.
Organizers of Saturday night’s Sole Sisters race were in contact with police all day ensuring the only obstacle for the 2,500 female runners is the heavy rain.
“It's unfortunate. The relay was in a hard situation. From what we understand the race was in the middle at the time and the made the best decision and shut it down,” said organizer Michelle Kempton.
Sunday's Walk to Fight Arthritis has been cancelled. On Facebook organizers blamed the bomb threat.
“The safety and well-being of our participants and volunteers is paramount. It is for this reason, after careful consultation with law enforcement officials that we've decided to cancel,” wrote the Arthritis Society.
Halifax police said they are examining surveillance tape to see if they can identify the person who called in the threat.