Embattled South Philadelphia High principal LaGreta Brown resigned Thursday amid questions about her certification.

According to the Pennsylvania Department of Education, Brown holds a state principal certificate but it is currently inactive.

A district official said that Brown had agreed to resign after the end of this school year, but after The Inquirer raised questions about her certification, she decided to leave the school Thursday, the official said.

In her resignation letter, Brown wrote that "it has become apparent that I have been made the focus of a controversy that continues to impede the education process to the detriment of the students."

For the short-term, Brown will be replaced by Ozzie Wright, a retired district principal who has been at the school in an administrative role since December.

Otis D. Hackney III, the current principal of Springfield Township High, will become the permanent principal. Hackney is a former district teacher who worked at South Philadelphia High as an assistant principal on a summer assignment.

Superintendent Arlene Ackerman met with staff at the high school this afternoon. As she left the building at 4 p.m. she said she had already spoken with the principal and told her she would not be returning to the high school next year.

"I felt the school needed new leadership," she said.

She said that right now "it's not a good learning environment for the children," and that "the children have to come to school tomorrow with another distraction."

Ackerman added that the school staff is deeply divided racially. "I'm going to go into that school and get to the bottom of it," she said

She promised to hold individual meetings with teachers about the direction of the school.

When asked how Brown was taking the ouster, Ackerman said "She's not happy. Would you be happy? She's resigning in the middle of the year."

Councilwoman Jannie L. Blackwell said she was surprised at Brown's resignation. Brown attended the Mayor's Commission on African and Caribbean Immigrant Affairs meeting with Blackwell on Wednesday night. Brown did not indicate at the time that she would resign.

"I thought she was sincere and trying to do a good job, and trying to improve things," Blackwell said outside Council Chambers Thursday afternoon.

High School math teacher Juan Acevedo said Brown's resignation was a "very sad thing."

"I agree with Dr. Ackerman," Acevedo said. "There is a great divide in the school among the adults."

Regional Superintendent Michael Silverman said the whole situation was sad.

Asked if the school system bore responsibility for not checking Brown's credentials more closely, he said "I'm not going to answer that one."

In a statement issued earlier in the day, Ackerman said the school has moved forward since Dec. 3 racial violence.

"We have spent the past several months making positive changes at South Philly High. These changes have brought about an improved climate for all students at the school. Violent incidents have decreased and more students are involved in after school activities," Ackerman said in the statement.

"I initially interviewed Mr. Hackney as a candidate for one of the Promise Academies," Ackerman said in the statement. "The interviewing committee and I were so impressed by him that it determined he was the right person to manage and lead South Philadelphia High next school year."

At the high school, Ackerman described Hackney as student-oriented, a former coach and someone with a great reputation.

Brown, who has been on the job less than year, has been a controversial figure. The school was rocked by racial violence on Dec. 3, when groups of mostly African American students carried out a daylong series of assaults on about 30 Asians.

Seven Asian students were taken to hospitals, and about 50 staged a seven-day boycott of classes.

Brown grew up in West Philadelphia and graduated from Girls High in 1979. In fall 2009 she became South Philadelphia High's fourth principal in five years, taking over a school that has long failed to meet state performance standards and been labeled "persistently dangerous" under federal law.

A federal civil-rights complaint filed against the district in January leveled several accusations directly at Brown, claiming she showed a discriminatory attitude toward Asian students.

Teachers reported that at a staff meeting before the start of the school term, Brown referred to the English-learners program, centered on the second floor, as, "That dynasty." Teachers believed that Brown had used the term as a disparaging reference to Chinese dynasties, the complaint said.

In the days after Dec. 3, the complaint said, Brown described community support for the students as "the Asian agenda." She repeated the phrase in front of teachers before a School Reform Commission meeting on Dec. 9, the complaint said.

The complaint alleged that as school ended on Dec. 3, and large crowds of students milled outside, Brown led and then abandoned a frightened group of about 10 Vietnamese students. The students were subsequently chased, surrounded by a mob of 100 and beaten. However, the official district inquiry said no evidence existed to show that Brown deliberately left the students. Instead, a gap developed between the Vietnamese and their adult escorts, the report said.

The district report on the violence said the assailants in the massive, dismissal-time assault included some white students and a female Cambodian. Asian community advocates said the key point was not the races of the attackers, but that all the victims were Asian.

Teachers had planned to take a no-confidence vote on Brown after school Thursday.

Instead, district officials arrived at the school to announce her departure.

Leah Harris, a spokeswoman for the state Department of Education, said Brown's principal certificate was issued in 2000 but was inactive "because she has not complied with ACT 48 requirements. Educators with inactive certificates are not permitted to serve in a professional position, they may only substitute teach for 90 days per school year until they comply with ACT 48."

Act 48 requires teachers and principals to complete continuing education.

Districts can be penalized for having teachers or principals without proper certification. The discipline, generally, comes in the form of the state withholding subsidies, Harris said.