CHARLOTTE - Twelve people have been taken from a Charlotte Harris Teeter grocery store to the hospital with apparent carbon monoxide poisoning, officials with Medic report.

At least one of those patients has a life-threatening condition.

There are multiple reports from the scene that at least six of those hospitalized were working at the store, which is at West 6th and Pine streets. The store was not open at the time.

Medic also has confirmed that several firefighters and emergency medical services personnel were taken to the hospital for precautionary reasons after complaining of illness.

The store was evacuated for about an hour, but employees are being permitted to go back inside the building now, in hopes of opening the store to customers later this morning. Authorities were not forced to evacuate any residents from townhouses in the same building, above the store. No evacuations were required from neighboring buildings, either.

There are indications that the incident might have resulted from fumes from a piece of equipment being used to clean the store.