Six people were taken to local hospitals after an apparent carbon monoxide release, Clovis Fire Department officials said.
Fumes from nearby construction work got into the ventilation system of a medical office building at 90 W. Ashlan Ave. early Tuesday afternoon.
At 1:32 p.m., Clovis Fire Department went to the building and found employees complaining of respiratory problems, headaches and nausea.
Firefighters determined that there were elevated levels of carbon monoxide in the building. The levels were not immediately life-threatening and more than 40 occupants were evacuated as a precaution.
Firefighters were successful in bringing the carbon monoxide levels down to acceptable limits by opening doors and windows to ventilate the structure.
By 3:30 p.m., employees had been allowed back into the facility.
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