UPDATE: Fire crews rule mysterious odor safe

TUCSON, AZ (Tucson News Now) - Northwest Fire District and Golder Ranch Fire crews have determined that the mysterious odor that caused two people to feel ill Thursday afternoon was not hazardous.

Crews responded to a medical office near Ina and Oracle Roads after receiving reports of a strange odor that was causing nausea, according to a press release. A Hazardous Material crew was also called to the scene.

Firefighters evacuated the building of roughly 30 people, and the Hazardous Materials crew used air monitoring devices to test the quality of air.

The monitors did show an unknown substance, but it was not carbon monoxide, sewer gas or any other hazardous substance.

The building was ventilated with positive pressure fans and ruled safe.