Here's a link with a bit more detail.... http://www.wowktv.com/story/24796783/carbon-monoxide-detected-at-ny-mall-eatery-1-dead Not sure what 'faulty heating system' means but it could be as simple as a cracked flue pipe or heat exchanger.
In 2009, several tour buses parked close to ventilation shaft at an ice arena (during a major tournament) in Illinois caused an evacuation and sent several individuals to a hospital