Pontiac — Anyone in downtown Pontiac early Monday morning might have heard a “boom” coming from the site of the old Phoenix Center.

It was the sound of the final above-ground structure of the old open-air amphitheater — a concrete staircase leading to an elevated platform — falling to the ground during demolition to make sure for a major new county development.

The demo, which started in late April this year, paves the way for an ambitious plan to eventually relocate up to 700 county employees to downtown Pontiac by 2027.

County officials purchased two buildings in downtown Pontiac, the old General Motors building at 31 E. Judson St. and another at 500 Woodward, along with several nearby vacant plots of land and the Phoenix Center, in August 2023. They plan to rehabilitate the Judson Street property and relocate at least three departments to the new Pontiac facilities, including the county executive’s offices.

They also plan to build parking garages with more than 1,000 total spaces and 21 charging stations for electric vehicles, and adding green space to the area. The project is estimated to cost more than $260 million in state, federal and county dollars, according to county officials.

“The significance here is, this is part of the demolition project that’s going ahead with getting rid of the last remnants of the Phoenix Center,” said Oakland County Deputy Executive Sean Carlson during the Monday morning demolition. “We’re going to bring down these stairs, and that’s the last thing remaining from the physical above-ground demolition. Once that’s taken care of, we’ll start to clear the ground.”

As the sun rose Monday, construction crews operated what’s called a “dinosaur” demolition tool to crush the concrete columns that held up the platform at the top of the staircase. Sections of the platform broke off and crashed to the ground as each column was crushed.

“It’s a great day,” said Carlson, who is running for State Senate. “This is big momentum.”

Critics have questioned the cost-effectiveness of the plan to move employees and offices to downtown Pontiac, but supporters have argued it’ll be more cost efficient the renovating the county’s current facilities at its campus on the Waterford-Pontiac border, which need millions of dollars in upgrades, they say.

Pontiac City Council President Mike McGuinness pointed out that the development project will also connect Saginaw Street to be a complete thoroughfare through downtown. He said this coincides with Michigan’s efforts to convert the Woodward Avenue loop, which encircles downtown, into a two-way street.

McGuinness, who is running to become Pontiac’s next mayor, believes the project will also bring business and foot traffic to the area.

“The layout and the construction plans have intentionally made it so that it is harmonious with the existing fabric of the downtown. So a big factor is that we’re going to have a lot more accessibility and navigability to and through downtown Pontiac,” McGuinness said.

McGuinness called the county project a “game changer.”

“It’s just so much vitality, and right in the heart of our downtown,” he said.