SIMI VALLEY (CBSLA) – A hazmat incident caused a hazardous materials chemical fire at an industrial building in Simi Valley Tuesday morning, prompting evacuations of several nearby businesses and forcing residents to shelter-in-place for more than four hours.

The hazmat incident was first reported at 6:16 a.m. in the 100 block of West Cochran Street, which is located in a business district, according to the Ventura County Fire Department. An employee who works in the building reported that nitric acid tanks were on fire, according to Simi Valley police.

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June 25, 2019. (Ventura County Fire Department)

Hazmat crews and firefighters responded and began evacuating Cochran Business Park. Plumes of smoke could be seen billowing hundreds of feet into the air.

A shelter in place order was also issued for businesses from Cochran Street to the 118 Freeway, and from East Street to First Street. The area has several stores, including a Costco, which were forced to temporarily close. Nearby homeowners were also ordered to shut all their windows and doors and stay inside.

(Ventura County Fire Department)

Forward progress on the fire was stopped sometime before 7:44 a.m., VCFD reported. However, the evacuation and shelter-in-place orders remained in place for several hours. They were not lifted until just after 11:30 a.m., when all surrounding stores were allowed to reopen.

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Nearby roads were also shut down during the incident, but have since also reopened.

The exact causes of both the hazmat situation and the ensuing fire were not immediately released. There was no word of any injuries.