CHICAGO (WLS) -- Don't be alarmed if you hear simulated gunfire and flash bangs around Wrigley Field Thursday.The city is plans what it's calling "an emergency response exercise". It will simulate a large scale active shooter incident and response at a major sporting facility, and will involve the Chicago Police Department, Chicago Fire Department, Office of Emergency Management and Communications and the Chicago Cubs.The drill is scheduled to take place between 7 a.m. and 2 p.m. Chicago police say it was planned at least six months ago to coincide with the All-Star break.To accommodate the drill, Waveland Avenue will be closed to both vehicle and pedestrian traffic from Clifton and Kenmore avenues for the full duration of the exercise.