NEW ORLEANS — More than 500 people turned out for a meeting Saturday morning to show their support and discuss options to keep Xavier University Preparatory Academy open after an announcement Wednesday night of the school’s closure stunned, devastated and galvanized the community.

The Catholic high school for girls at 5116 Magazine St. was founded by St. Katharine Drexel and the Sisters of the Blessed Sacrament in 1915. The sisters, who are based in Pennsylvania, issued a statement saying that “after reviewing the financial projections for the 2013-14 school year, the Sisters concluded that the Prep does not have a financially sustainable future.”

On Saturday, the meeting in the cafeteria of Dr. Martin Luther King Charter School filled to the point that it became almost impossible to get into the door. Most in attendance were alumni, parents of students and current students proudly wearing their uniforms.

Prep principal and President Joseph Peychaud spoke to the crowd about the options looking forward. The two alternatives he first discussed were either purchasing the property or leasing to own it. Peychaud estimated the market value of the prime parcel of Uptown real estate at somewhere between $4 million and $6 million — an estimate he called conservative.

He talked about two options in terms of Xavier Prep remaining a Catholic school. The first, being owned by the congregation, is no longer an option, he said. The other is to operate under the auspices of the Archdiocese of New Orleans.

To stay open under the archdiocese, Peychaud said, a core group of supporters would need to quickly come up with an operating budget. He estimated the operating costs at $2.7 million per year.

Beyond making a down payment, Peychaud stressed that to realistically pitch buying the facilities, those hoping to take over the school also would have to show how they could sustain its costs into the future.

Jan Lancaster, superintendent of Catholic schools in the archdiocese, said the archdiocese had offered the sisters financial support, but only enough to keep the school open for another year. “We don’t have the resources to sustain the school for the long term,” Lancaster said.

The sisters declined the temporary support, according to the archdiocese, and could not be reached on Saturday for comment.

Peychaud acknowledged during Saturday’s meeting that parents, without knowing for certain if they can quickly generate the dollars needed, “have to make a choice” in terms of making sure their daughters have a school to attend in the fall.

“We can’t ask to them hold on and hold on and lose other options,” he said.

The application process for Catholic schools already has passed, with the announcement of Prep’s closing coming the same week that families received letters in the mail from the archdiocese regarding the schools where their children had been accepted.

Lancaster said there are enough seats in other Catholic high schools to absorb the 245 Xavier students, and that many schools already have reached out to help.

Peychaud left the conversation open to other “creative” options to keep the school open. Also discussed were the possibility of moving to another facility, tuition increases and returning to a coed population, which the school had until 1970.

Peychaud put the time frame needed to raise the money as “not beyond 30 days.”

Kimberly Dilosa, a 1992 Xavier Prep alumna and one of the organizers of efforts to keep the school from closing, said that based on the response she already had received from high-profile and celebrity alumni and supporters, and based on the number of people who showed up for Saturday’s meeting, “We can raise $10 million in 30 days.”

Actor Wendell Pierce tweeted on Wednesday, “A sad day when a New Orleans institution like Xavier Prep comes to an end. It was against the law for blacks to get educated, Prep was there.”

On Thursday he tweeted, “Xavier Prep has to be saved. New Orleans has lost its way if we rise to save/support Hubig’s Pies but not this iconic school. $ can be raised.”

About halfway through Saturday’s two-hour meeting, when the microphone was opened to questions and comments from the public, any news reporters inside the building were asked to leave, in spite of being invited to attend earlier in the week.

And despite sending out a news release and widely using local media outlets to get word of the meeting out, Peychaud incorrectly accused any reporters inside the meeting room of sneaking in. He asked all of them to leave immediately, and instructed people in the audience to give no comment to requests for interviews and to let him respond to the press instead. “That way, we can control the message,” Peychaud said.

Outside, 1997 alumna Zenia Williams held up a glittered sign she made in support of keeping Xavier Prep open. Williams said her time at Prep provided the foundation for her education, and gave her a sense of strength and pride. “What Xavier Prep has instilled in us can’t die,” Williams said. “It has to go on.”

Dilosa said the XUP Foundation Fund has been set up and will accept donations by mail at 5116 Magazine St., New Orleans, LA 70115.