The Calgary Fire Department said they received a report at around 11:05 a.m. indicating the ammonia alarm at the Rocky Ridge YMCA had been activated.

When crews arrived, the building was already being evacuated.

CFD Public Information Officer Carol Henke said the alarm had detected ammonia at around eight parts per million in the room where the leak originated.

“Even a lower amount would be really uncomfortable. It would cause your eyes to sting and water, and is dangerous to breathe in,” said Henke.

This is the third time in just over a week that the ammonia monitoring alarms had been activated, after first triggering on July 3 and then again on July 5.

In a statement to Global News, YMCA Calgary officials said the evacuations are disruptive and they apologize for any inconvenience caused to those attending the facility.

“Our monitoring systems and safety protocols are working as intended – and that is a positive outcome. This means that our systems are effectively detecting and responding to even trace amounts of ammonia, ensuring the safety of everyone in the facility,” said YMCA Calgary.

YMCA Calgary added they’re continuing to work with experts to review today’s incident and determine if any additional measures are needed, as they try to figure out the root cause of the issue.