According to EMS workers who spoke to CBC News, they were stretched so thin on Sunday night that there were barely enough crews to cover large parts of the city.
Paramedic Roberta Scott says that happens all too often.
Anger over the issue peaked at a meeting on Wednesday night, which has prompted some paramedics to send a message by refusing to work overtime.
Scott has written to the mayor and to city councillors about the issue.
"The city is running on basically bare minimum coverage, so we’re saying that you don’t have enough cars on the road right now, you don’t have enough ambulances," Scott said.
However, Deputy Mayor Doug Holyday said more staff would cost too much.
Instead, he would like to change staff schedules, which Holyday claims haven’t been updated in more than three decades.
"We need to be flexible enough to bring them in when we need them and let them go home when we don’t need them," Holyday said.
"And that’s only good management and that’s all we’re asking for."
While Holyday said his proposed changes would improve efficiency in the system, Scott said the main problem is that with fewer staff, response times are lagging.
"What we’re all worried about is the next step … someone is going to die unnecessarily because they didn’t get an ambulance in time," said Scott.
Click on the video above to see a full report from the CBC’s Steven D’Souza.