Girard, IL –  “At least 150 people were treated at hospitals for the incident, which occurred the morning of Sept. 15, 2014. After a handful of students came forward with symptoms of carbon monoxide poisoning around 9 a.m., school officials made the call to evacuate.  The lawsuits, which names the school district, as well as several contractors and architects, says the leak originated at two natural gas boilers, which the school utilized to generate its hot water. An employee with Springfield-based HVAC company Burgess & Son was performing maintenance work on the boilers the morning of leak, and according to the lawsuit, failed to repair a “break or separation of a vent pipe connection in the vent system for the aforesaid hot water heaters.”

https://www.thetelegraph.com/news/article/Three-more-lawsuits-filed-in-2014-North-Mac-12729370.php