What if, on a hot summer morning, a powerful tornado were to touch down in central Denver, leaving a widespread path of damage, creating a prolonged power outage across most of the city, and possibly the airport?

That’s exactly what the city’s Office of Emergency Management, along with close to 140 participants and agency representatives, aimed to find out on Thursday as “Denver Mile High Ready 2025” got underway deep in the basement of the city government building.

Denver’s emergency management experts and city partners gather regularly to study, test, and evaluate how the city — and its available resources — would respond to a large-scale disaster.

“One of the things that I wanted to get out of this particular exercise, because it’s a growing concern of mine, is (response to) a long-term widespread power outage,” Denver Emergency Management Executive Director Matt Mueller said.

Nestled inside the city’s Emergency Operations Center, exercise participants from law enforcement, transportation and infrastructure, weather, housing, medical and other organizations work amid computers and phones to handle the simulated disaster.

While many of the simulated problems “injected” into the training scenario may seem far-fetched given the compressed seven-hour timeframe, they are designed to challenge the present and refine the future.

Such exercises are often required for the city to maintain accreditations and meet various government and grant requirements, but they also offer essential, localized benefits.

Exercises provide an opportunity for the city to strengthen coordination between agencies, test new processes and identify gaps, said Loa Esquilin-Garcia, communications manager for the Denver Department of Emergency Management.

Those gaps can range from communication between public and private sector partners to resource shortages to missing or insufficient elements in responder training.

The city’s coordinated response to local news media is also put to the test.

For Xcel Energy, the event offered the opportunity to improve awareness and coordination with the city.

“The scenario simulated today is that a tornado touches down in unincorporated Adams County, in the far northeast corner of the city, which impacts our equipment,” Grace López Ramírez, Xcel’s senior manager of government affairs, told The Denver Gazette. “This would impact our (electric) transmission and distribution lines … a transmission line that goes down 56th Avenue from east to west, and then a substation.”

Such an event, López Ramírez estimates, could take anywhere from three to seven days to restore power, depending on the severity of the damage.

“Exercises, like today, help us identify any gaps in the coordination and planning to ensure that we are able to energize that critical infrastructure that the city needs, not just for traffic control, for, you know, critical entities like local hospitals, and rec centers that might be being used for unification,” she said. “So what Xcel is doing in this particular exercise is looking at how to most safely and efficiently bring assets back online in a coordinated effort that benefits all of the stakeholders.”

Elsewhere, at the joint information center, public information and media relations personnel from different agencies vetted and coordinated the release of information to the public and simulated media outlets.

Major agencies participating in the exercise include the Denver Department of Public Health and Environment, Xcel Energy and the American Red Cross.

A lot of planning and effort goes into a functional exercise, such as this, Mueller said, with exercise designers creating detailed scripts with a specific sequence of events to test responses.

Funding for exercises is included in OEM’s annual budget.

So, how did the city do?

That will come later, Mueller said.

“We will have a better answer to that in a few weeks once we get all of the feedback,” he said. “We take all of that, we roll it up, and we create an after-action report which identifies some of those gaps and things we need to get better at.

“This is why we practice, so we make the mistakes now and not when the real thing happens.”