Man with chain saw killed by police at senior facility in St. Charles, Illinois

Police in Illinois fatally shot a man who they say threatened residents at an assisted living facility and responding officers with a chain saw.
Officers in St. Charles, a city about 40 miles west of Chicago, were dispatched around 8:45 a.m. Sunday to the River Glen of St. Charles senior living facility for a wellness check after they received reports of a shirtless man holding a chain saw and attempting to cut down a tree on the facility's property.
Just before officers arrived, witnesses said the man barged into the building lobby and "began confronting residents with the chain saw," according to the St. Charles Police Department. Officers tried to de-escalate the situation, but the man "continued his attempts to use the chain saw against residents of the building."
Police used a stun gun, but it didn't stop the man, the department said in a statement. An officer then pulled out a gun and shot him.
Police rendered first aid at the scene before the man was taken to Northwestern Medicine Delnor Hospital, where he was pronounced dead.
The man's name has been withheld pending a first-of-kin notification, police said Sunday. It remains unclear why he entered the building or whether he had any connection with the facility or its residents.
Several people, including residents of the assisted living facility and responding officers, were treated at the scene for minor injuries. Police did not say what caused their injuries.
About three hours after police received their first report about the man with the chain saw, the department said in a Facebook post that there was a large police presence at the facility and asked people to avoid the area. The post also assured people there was no danger to the public and added that they were not looking for any other people in connection with the incident.
The Illinois State Police agency is leading the investigation of the officer-involved shooting, as is standard protocol, the St. Charles Police Department said.