Updated

Dozens of people were evacuated from a psychiatric hospital in Mesa, Ariz., when police who were trying to coax a runaway patient out of an air vent inadvertently spread toxic fumes throughout the building.

Mesa police responded to Desert Vista Behavior Health Center when a patient there reportedly tried to escape by crawling into an air vent, MyFoxPhoenix.com reported.

An officer deployed pepper spray in the vent in an effort to coax the patient out -- but fumes traveled through the vent to the entire floor.

More than 50 people were evacuated -- including the person who had been trying to escape -- after residents and staff complained of difficulty breathing.

Patients were taken to a hospital across the street for evaluation. 

Click here to read more about this story from MyPhoenix.com.