Police said at about 5:15 p.m. their west central dispatch received a call from a crisis intervention line to inform them a woman had called and threatened to do harm both to guests at the zoo and to herself.
The zoo's police force reached out to Brookfield and Riverside police departments, as the zoo facility straddles both towns, who sent officers in response.
Despite the vagueness of the threat, police decided to issue a lockdown and shelter in place order out of an abundance of caution. They then worked to clear each public area and private areas for staff, keepers and animal houses.
The caller was not found and all zoogoers were safely escorted out by 8:10 p.m. after they were forced to shelter-in-place, police said.
«In light of the Highland Park shooting, we wanted to do everything in our power to keep our zoo and animals safe,» police said.
«Out of an abundance of caution, visitors at Brookfield Zoo right now are asked to shelter in place and follow guidance by emergency responders and police on site. This is a developing situation, and we will give you updates as they become available,» the zoo originally posted.
The FBI is involved and the suspect who made the call is not in custody at this time.
What a crazy night it must have been for the people present at the zoo...