More than 75 students at the Iowa Law Enforcement Academy were hospitalized because of carbon monoxide poisoning, according to NBC News.

The cadets—all newly hired law enforcement officers still in training—were evacuated and initially taken to a nearby National Guard building.

The cadets were then transported to various hospitals in the area after they started experiencing symptoms which included nausea, headache, and fatigue.

There are 97 students total in training at the academy. Bradshaw said 11 of them were not in the building at the time of the incident.