By Blair Crawford, Ottawa Citizen, March 24, 2017
A portion of the Rideau Centre was evacuated briefly Friday afternoon after a carbon monoxide detector in one of the stores sounded a warning of high levels of the potentially deadly gas.
Firefighters were called to the mall just after noon and confirmed elevated carbon monoxide levels of between 30 and 50 parts per million. While firefighters, police, paramedics and mall security evacuated the first floor, firefighters used fans to ventilate the affected area. The department’s Hazmat team monitored air quality throughout the mall and carbon monoxide levels soon returned to normal.
http://ottawacitizen.com/news/local-news/carbon-monoxide-scare-prompts-rideau-centre-evacuation