Authorities are trying to determine what made several employees at Joshua Tree National Park suddenly become ill.
A park statement says the administrative headquarters was evacuated and closed Wednesday afternoon and hazardous materials teams were called to the scene. The employees reported a sudden onset of symptoms, including skin irritation, respiratory distress, nausea and eye irritation, after working in the park's mailroom.
Officials say a hazmat team decontaminated 11 workers.
A package delivered by a commercial carrier earlier Wednesday was identified as a possible source of the contamination.
KCDZ-FM says the package had a stain on it.
Park officials say no visitors were exposed to any contamination during the incident.
Hazmat teams were not able to determine the source of the contamination and the cause was still under investigation.