The Minneapolis school board on Tuesday night awarded a long vacant but highly sought-after school property to a charter school partner to expand its network of successful charter schools.

But the 6-1 vote left supporters of redeveloping the block for senior housing sought by the neighborhood deeply disappointed. The building closed in 2005.

Hussein Samatar cast the only vote against the proposal to sell the property for use by Hiawatha Academies for its third school. Josh Reimnitz and absent Alberto Monserrate abstained because of personal conflicts of interest.

The vote dramatized the degree of the district's commitment to a new era of district-charter school cooperation the board set about five years ago after years of rivalry. Superintendent Bernadeia Johnson recommended the deal with Hiawatha.

"This is an opportunity for district and charter schools to work together to close the achievement gap, regardless of what school the students are going to," said an excited Eli Kramer, Hiawatha's executive director.

Johnson said it's important that the district support high-quality schools regardless of whether they are district or charter schools. The district in January signed an agreement to cooperate with Hiawatha.

Supporters of Hiawatha — parents, students and board members — packed the meeting to beseech the board to sell the building to the school. They pointed to Hiawatha's academic success with a mostly low-income and Latino student body. It outperforms district students in state math, reading and science test scores.

Hiawatha said it would invest $4 million in the building and grounds and shift its new elementary school, which it plans to open this fall in existing space, to Northrop in fall 2014. The school would eventually hold 390 kindergarten through fourth-grader students.

Neighborhood group president Stearline Rucker demurred. "I am just stunned," she said. "I am just shocked that the district did what it did."

Kramer said a proposal for splitting the block on which the school sits between Hiawatha and developer United Properties won't work for the school. He said that would slow the school's timetable and impinge on the space the school needs.

Some board members expressed disappointment over Hiawatha's unwillingness to split the site, although United was willing. But board member Richard Mammen disagreed: "We're not in the business of shotgunning a marriage between United Properties and Hiawatha."

City officials had favored the United proposal to build at least 30 units of senior housing on the block, while renting the school to a charter school. Supporters said that would create more than $5 million in new tax base and noted than United offered $200,000 more for the site than Hiawatha's $1 million.

Robert Jansen, an area resident, argued that aging city residents have few options for senior housing compared with the suburbs.

Steve Brandt • 612-673-4438 Twitter: @brandtstrib