Phoenix fire crews were called out to the JW Marriott Camelback Inn Saturday night after reports of a possible carbon dioxide leak.
Paramedics evaluated four patients at the scene. No injuries were reported and no one was taken to the hospital.
Fire crews continued to investigate the possible leak with gas meters that measure for CO and CO2.
"Fire crews metered and found negligible readings of CO2," read a statement from the Phoenix Fire Department. "Fire crews are working with the building engineer currently and will remain on the scene to assist."
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