CHICAGO — Chicago police, firefighters and paramedics were among the hundreds of personnel involved in Friday’s active shooter drills, conducted at an unsuspecting City Hall.

“To stop these events is nearly impossible. We see them happening across the country every day,” said Deputy Chief Duane DeVries with CPD’s Special Operations and Counter Terrorism, who says a rapid and coordinated response was the purpose behind the drill.

Securing a busy public space, like City Hall, and evacuating the wounded with an active shooter still in the building was an immediate logistical challenge for the participants. But city departments training together, DeVries says, will pay big dividends to their response.

“We have partners from all different agencies. We get to see these people in play,” DeVries said. “See what their actions are, see our counterparts.”

Prevention in the form of a hardened target is part of the mix when defending high-profile places like City Hall. Police commanders say much can be learned by studying how law enforcement responds to the kinds of threats around the country, including the sorts of mistakes and communication problems during the tragic response in Uvalde, Texas.