KANSAS CITY, Kan. — A plant in Kansas City, Kansas is open but under investigation less than a day after dozens of employees became sick.

The Kansas City, Kansas, Fire Department said it arrived at Premier Custom Foods near South Mill Street and Pawnee Avenue shortly before 2 p.m. Tuesday.

The fire department said one person was unconscious by the time crews arrived.

Of the 80 people who work at the plant, emergency crews said they treated 30 people. First responders transported 16 employees to hospitals.

“We found a number of different people getting very, very sick, very ill,” Assistant Fire Chief LaRwan McLaine said.

KCK Fire mobilized its hazardous materials procedure during the response. McClaine is proud of the team effort in a tough situation.

“They remained calm, their training kicks in and they handled the situations the way that they’re trained to handle them,” McLaine said. 

FOX4 reached out to the company; a spokesperson released the following statement:

“We are glad to update, our employees are all safe and healthy. We thank the KCK Fire Department for their fast response and assistance. All products at the facility are safe and not contaminated. This incident is under further investigation, therefore, there will be no further comment.”

The U.S. Department of Labor said it’s investigating. The department said a possible carbon monoxide leak inside the building sickened the employees.

The Occupational Safety and Health Administration said the plant uses carbon monoxide at the plant to preserve fresh meat. At this point, it’s only preliminary information.

OSHA has six months to complete its investigation into the issue.