"Think of it like 911. It’s going to summon police, fire and paramedics," said TTC spokesperson Brad Ross.
Ross said that in the first nine months of this year, some 2,200 alarms were activated on subway trains. But, only 700 were "true emergencies," he said.
Each time the alarm is pulled, a delay of two to 20 minutes ensues.
Ross said that delay affects every train in operation.
Click on the video above to see a full report from the CBC's Lucy Lopez.