CHICAGO (WLS) --Wrigley Field was the scene Thursday for a worst case scenario. Hundreds of law enforcement officers participated in an active shooting drill.
The drill involving flashbangs and simulated ammunition was meant to keep fans safer in and around the ballpark.
The operation allowed Chicago's emergency crews to practice how they would respond to a large-scale active shooter incident at the Friendly Confines. Waveland Avenue was closed from Clifton to Kenmore Avenues to pedestrians and traffic during the drill, which was scheduled to last from 7 a.m. to 2 p.m.
The Chicago Police Department, Chicago Fire Department, Office of Emergency Management and Communications and the Chicago Cubs participated in the training session, which they tried to make as real as possible. About 100 people dressed as Cubs fans acted like victims and sound effects helped make it seem like an actual game was in progress.
"Two bad guys will walk through these gates, Gate J. They're going to have weapons and they're going to start shooting," said Deputy Fire Commissioner Mark Nielsen, Chicago Fire Department.
ABC7 cameras were not allowed inside the stadium during the drill, in order to keep the tactics SWAT officers use in these situations under wraps. The fire commissioner said practice means preparation.
"The more you do these things, it makes you better. It makes it more muscle memory. It's always beneficial," Nielsen said.
The emergency response exercise has been in the works for about six months and was planned to coincide with the All-Star break. It was not being done in response to any recent local or national shootings.
Wrigleyville residents said they would have liked more of a heads up about Thursday's training exercise, which was sure to be loud.
"I had no idea what was going on. I thought it might be a bomb threat with all the police lined up out here," said Kyle Fahey, who lives near Wrigley Field.
"It makes me feel a little bit safer, I wish I just knew more about it and that it was happening. I just happened upon it today. But it makes me feel safer that they're taking precautions," Elizabeth Simmons, a resident, said.
The owner of the Cubs watched from outside the park.
Some residents also watched and tell ABC7 they had been informed about the drill.
"I'm glad they are doing this so they can be prepared. So that the police and the fireman if they had to come here, they would know what to do, and the Cubs employees," Linda Barry Jachim, a resident, said.
"It's a good thing, I work in a school not far from here, and we practice it with the students. I think it's something you have to do in today's day and age," Matt Pope, a resident, said.
Waveland was opened by 2 p.m. With all of the construction going on around Wrigley Field, it would have been hard to tell a drill was taking place if someone was just passing by.