ANTIOCH (CBS SF) – Fire investigators believe the substance that sickened 11 people inside a JCPenney store in Antioch on Tuesday was possibly pepper spray, according to a Contra Costa County Fire Protection District spokesman.

Fire officials first reported the trouble at about 7:30 p.m.  inside the store at 4951 Slatten Ranch Road.

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“Once we arrived on scene, we had 11 people complain about some type of problems breathing,” Fire Inspector Steve Aubert said.

All of the victims complained of breathing trouble and two people were taken to the Kaiser Permanente Antioch Medical Center for treatment, Aubert said.

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Hazardous materials crews were able to clear the store by 9:30 p.m., Aubert said.

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