NEW ORLEANS (AP) — A possible end to New Orleans’ 70-year legacy with public housing came in an unanimous city council decision Thursday, but it took pepper spray, Taser guns, and faces pushed to the asphalt for the vote to transpire.

In a day of inflamed passions that began with public housing advocates lining up to enter city hall at 7 a.m. CST, the council voted some eight hours later to begin the demolition of 4,500 units that some called blight, and others called home.

The council’s decision, many believed, set in a motion a sweeping character change for New Orleans that was made possible when Hurricane Katrina submerged it in floodwaters over two years ago.

‘‘I think it was a done deal last week,’’ Rev. Marshall Truehill Jr., a local minister and housing advocate said minutes after the tally. ‘‘I think they have been coerced by HUD and people with influence, power and money.’’

Council member at large Arnie Fielkow said the city is seizing the opportunity to remake itself as a place of prosperity, instead of violent crime, fractured schools and social iniquities.

‘‘The truth is much of our beloved city was broken before Katrina,’’ said Fielkow. ‘‘Quite simply, our residents deserve better.’’

About a third of the people who stood before the council to testify on behalf of saving the projects had ever lived there, but they said there was a tragic reason why more residents could not speak for themselves.

‘‘If they weren’t scattered across the country, with no home to return to, there would be more of them here,’’ said Tracie Washington, an attorney who advocates on behalf of tenants.

Mayor Ray Nagin, absent from the council session, brokered compromises on Thursday with HUD Secretary Alphonso Jackson on how the redevelopment plan will be carried out. Private developers are planning to build mixed-income communities to replace the projects, but critics said Nagin’s agreement amounted to minor changes unlikely to effect the sweeping loss of affordable housing stock.

Nagin said HUD’s promise to allow more local oversight and to redevelop in phases would ‘‘not be empty promises but words in action’’ ensuring that ‘‘every resident has the right to return.’’

But even as city officials paved the way for demolition of the units, housing advocates reached for decreasing options to save the four public housing complexes built in the brick styles of the 1930s. Some said the police-protestor standoff outside the chambers violated public meetings laws, because it kept voices from being heard.

‘‘Is this what Democracy looks like?’’ asked Bill Quigley, a Loyola University law professor who opposes demolition, a tangle of Taser wire in his palm that moments before was launched at a protester. Quigley said he would explore a legal case aimed at invalidating the proceedings.

But Ann Heath, an attorney with the Public Affairs Research Council, an independent public policy research organization, said unless the chambers were grossly under capacity, the advocates would have a thin claim. There were about a dozen empty seats at the council session at any given time, according to reports.

‘‘If somebody approached me in my old law office to take that case, I would probably decline,’’ she said.

Some public housing residents said during the daylong debate that they welcome the plan by the U.S. Department of Housing and Urban Development to scrap the decades-old structures and replace them with mixed-income units. The structures were damaged in 2005’s Hurricane Katrina, but advocates say most were still habitable.

HUD says about 3,000 families who once lived in New Orleans public housing remain scattered across the United States, and social workers say the number of homeless people in the area has doubled to about 12,000. About 200 of the homeless live in a plaza in the shadow of city hall, taking shelter in tents bought from a local Wal-Mart.

After roughly 30 minutes of on-again-off-again struggle to get into the meeting, protesters fell back, continuously chanting with bullhorns and voices that grew hoarse. An afternoon rainstorm thinned the crowd, but at the peak of the confusion about 70 people were facing about a dozen mounted police and 40 more officers on foot. One sheriff’s deputy wept on the city hall side of the gate as he stood shoulder-to-shoulder with other officers blocking passage.

‘‘They did not use excessive force in any way,’’ Police Chief Warren Riley said of the confrontations with his officers.

‘‘I was just standing, trying to get into my City Council meeting,’’ said one dazed woman, Kim Ellis, who was taken away in an ambulance with a strand of taser wire dangling from her shirt.

Police said 15 people were arrested on charges ranging from battery to disorderly conduct both in and outside the meeting.

Jean Nathan, a spokeswoman for some demolition opponents, acknowledged that the groups had few governmental options left to save the projects. More radical groups, including Black Panther Party member Krystal Muhammad who was arrested on Thursday, said they had not ruled out nonviolent action to block the bulldozers.