An accidental trip of an alarm prompted a police response at the Alexian Brothers Behavioral Health Hospital in Hoffman Estates on Thursday morning, authorities said.
A police department spokesman told NBC Chicago at about 10:40 a.m. that officers were going through the facility, at 1650 Moon Lake Boulevard, to make sure everything was clear.
Police earlier said they responded to the clinic amid a report of a person with a gun but said throughout the incident they had the situation "under control."
About a dozen people were seen from NBC Chicago's helicopter leaving the building with their hands in the air at 10:30 a.m.
Nearby Hoffman Estates High School was put on a soft lockdown "due to an emergency situation in the area," according to a post on the school's website. That lockdown was listed just after 11 a.m.
