It was a sad moment for me when I watched, on YouTube, a video of the March meeting in which members of the Mystic Historic District Commission gave permission to the new owners of 17 Gravel Street to tear down the iconic, much-photographed cottage on the Mystic riverfront.

It wasn’t even a live meeting. The deed was already done. There was no point even in shouting at my computer screen, like you might at a receiver who fumbles an easy catch on live television.

Incredibly, the Groton commission charged with protecting the integrity of the Mystic River National Register Historic District completely forsook its mission, agreeing to the total demolition of one of the more interesting buildings in its stewardship.

There wasn’t even any testimony that there was any structural problem with the building.

That’s the bad news, that a commission that is supposed to be dedicated to preservation decided, remarkably, on the polar opposite: a demolition.

The good news is that the community rose up against this monumental bad decision. And the state’s historic preservation machinery whirred to life in Mystic.

Todd Levine, architectural historian with the State Historic Preservation Office, which intervened after the strange March demolition vote by the Mystic commission, said Tuesday an agreement with the owners to save the principal structure and historic façade of Downing Cottage is being finalized.

The Mystic River Historical Society, in cooperation with Preservation Connecticut, the private partners of the historic preservation office, circulated a petition in the community that secured 3,566 signatures of people opposed to the demolition.

The state preservationists said they were prepared, as they have done with other threatened demolitions in the region of historic buildings, to go to court to stop the destruction of Downing Cottage.

A judge could have been asked to find that the building, a contributing structure to the National Register of Historic Places, is protected from demolition as a natural resource, provided alternatives to its destruction exist.

The owners and their architect got the Mystic Historic District Commission to agree to the demolition with an argument that it would be too difficult to raise the building to satisfy flood plain requirements.

The commission’s split vote to accept this premise was a harbinger of other similar decisions that might follow, because so much of the district is in a flood zone.

Levine told me Tuesday the owners, Dan and Jennifer Grace, have now agreed instead to save the principal block of the old house and its façade and raise it the required amount necessary to accommodate flood regulations.

In addition, he said, they will do extensive landscaping in the front of the house to mitigate the visual impact of raising the building, so that it will continue to seem a natural part of the streetscape.

Levine said an agreement specifying the scope of the work and the preservation of the building is being finalized with the attorney general.

“We are in agreement to save the building,” he said, adding that the owners understand the reaction by the community to the proposed demolition.

“They recognized the potential backlash, and because they are going to be living in the community, they wanted to do the right thing,” he said.

Meanwhile, the state preservationists have suggested the Mystic Historic District Commission might benefit from the kinds of training they offer to community boards charged with preservation.

Education and training would always be helpful.

But I would suggest some resignations on the Mystic historic commission, certainly those who voted to allow the complete demolition of Downing Cottage, a bad decision in itself, but the also the setting of a terrible precedent.

Let the resignations begin with Chairwoman Sarah Moriarty, an attorney who presided over this shameful mockery of the commission’s core mission.

From a petition with the signatures of more than 3,500 people with respect for Mystic’s unique historic character, there must be lots of suitable candidates to better serve the community in this role.

This is the opinion of David Collins.

d.collins@theday.com