CHICAGO (CBS) – Dozens of firefighters rushed to the Nestle plant on the city’s Southwest Side overnight.

The ammonia leak was reported to the Fire Department at 9:30 p.m. Monday at 1821 S. Kilbourn Ave., Fire Media Affairs spokesman Richard Rosado said.

The Fire Department issued a precautionary Level II hazardous materials response and sent out five ambulances.

As of 12:40 a.m. Tuesday, the scene was secured and no one is reported injured, Rosado said.

The cause of the leak is being investigated, Rosado said.

The Sun-Times Media Wire contributed to this report.

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