CHICAGO (CBS) — We first showed you the images on Tuesday – hundreds of trees chopped down at a park alongside the Chicago River system.

As CBS 2’s Jim Williams reported Wednesday, the leveled trees in Legion Park shocked neighbors who did not see it coming. But Friends of the Chicago River said this is just the first step in a project that will actually improve the neighborhood.

Hundreds of trees were chopped down and carried away along the North Shore Channel of the Chicago River in Legion Park, leaving it looking like the aftermath of a tornado.

“It’s mindless, thoughtless, indiscriminate, heartbreaking destruction,” neighbor Janette Dingee said Tuesday.

Painful it may be to see the trees go. But it is also necessary, according to Margaret Frisbie, executive director the nonprofit advocate group Friends of the Chicago River.

“Because it’s a step-by-step process, and to start, you actually have to take down the trees that are there.”

So that the banks of the river at Legion Park can be shored up – stopping erosion, and creating a healthier ecosystem, Frisbie says.

“What we’re taking out is largely invasive plants. What you have are plants that don’t support our native wildlife, and replacing them with what kinds of plants that grew up here, evolved with our ecosystem, and belong in the Chicago area,” Frisbie said.

That work has already been done along the river ….just south of Legion Park.

“I don’t have an issue with the project, per se,” said Ald. Andre Vasquez (40th). “I think it makes perfect sense.”

Still, Vasquez insists the Chicago Park District and the Army Corps of Engineers should have done a better job telling the neighborhood that the trees would be coming down.

“You get a notice from people doing street sweeping,” Vasquez said. “To not do it for trees, and this many, and this large of a scale project, I think that was a big problem.”

And the disappearance of the trees was shocking for neighbors.

“I walked up and down here crying yesterday,” Dingee said.

But Friends of the Chicago River says the work will be well worth it.

“It’s really painful as a process, but what we know is in five years, it’s going to be gorgeous and people are going to be happy about it,” Frisbie said.

The Park District tells us the wood from downed trees will be used for new mulch trails and around new planted trees and shrubs.