CHICAGO – Fulton Market was the scene of a hazardous materials incident after 11 individuals were sickened by carbon monoxide, according to news reports.

Emergency crews were called to 1115 W. Fulton Market just before 11:30 a.m. Aspen Foods, a meat processor and grocery store, is listed under the address. Eleven workers at a meat-processing plant were taking to hospitals after reporting multiple symptoms, including headaches, dizziness and rapid heartbeats.

The cause of the carbon monoxide leak is under investigation.