CHICAGO -- Chicago Police and SWAT teams have a home surrounded on the city's West Side.
Police say that at approximately 12:30 this afternoon officers witnessed a man walking into a building on the 1200 block of S. St. Louis Ave. with a gun. They evacuated neighboring buildings and have been on the scene afternoon.
There have been no reports of injuries. It was not immediately clear if there is anyone else in the building.
Police said they have arrested at least one person and are now inside the home.
More details as they become available.
WGN's Kelly Barnicle contributed to this report.