11 Sickened At East Bay Department Store By 'Unknown Substance'

CONTRA COSTA COUNTY, CA -- Authorities are still investigating what caused 11 people to become ill Tuesday evening when some type of substance was released inside an East Bay department store, prompting evacuation of the building.

A hazardous materials crew responded around 6 p.m. to investigate the incident at JCPenney, 4951 Slatten Ranch Road, in Antioch, according to Steve Aubert, a fire inspector with the Contra Costa County Fire Protection District.

"Eleven patients complained of problems breathing or some type of coughing," Aubert told Patch. He said two of the patients were transported by ambulance to an Antioch hospital.

The store remained evacuated for more than three hours as the hazmat team sought to determine the source of the unknown substance. Pepper spray was initially suspected, Aubert said

"By the end of the call, hazmat had cleared the building and could not find anything that would cause a danger to anybody else," Aubert said. "At 9:30 p.m., we released the store back to the store management and they were going to continue with the Antioch Police Department for further investigation."

Bay City News Service contributed to this report.

Images via Contra Costa County Fire Protection District/Twitter