Despite a change in principals and a crackdown in security, chaos continued at West Philadelphia High School yesterday, with two fires set in the building, evacuations, threats against a teacher, and seven student arrests, officials said.

The student unrest has been fueled in part by the district's decision last week to remove Principal Clifton James after a rash of assaults on teachers and staff at the 1,100-student school at 4700 Walnut St.

But students weren't the only ones upset about the way James was removed.

Yesterday, the union representing district principals complained in a letter to district Chief Executive Officer Paul Vallas. The union has called a membership meeting for Thursday to discuss the issue, which especially riled principals because Vallas announced his decision to remove James in the newspaper.

"It's more or less disciplining in the paper. That's something we object to very strongly," said Michael Lerner, business agent of the 750-member Commonwealth Association of School Administrators, Local 502. "We do not want principals to be scapegoats for disciplinary problems that are systemic."

Vallas defended his decision.

"If a team is not winning, you don't change all the players. You don't replace the fans. You go out and change the manager," he said.

James did not return calls for comment yesterday.

Problems at West Philadelphia High exploded last week after teachers there complained that assaults on staff in some cases were being downplayed. Initially, Vallas said he would replace James soon but he speeded the process after another staffer was attacked. On Friday, several small fires were set in the school and another teacher was assaulted during an evacuation.

Despite an increase in security and adult volunteers, and the interval of the weekend, the school again was in turmoil when students returned yesterday morning.

"We haven't settled down in the sense of normal operations, but clearly we're working toward that goal," James Golden, the district's chief safety executive, said yesterday.

According to city police, yesterday:

A male student threatened to strike a female teacher with his fist; he was charged with making terroristic threats.

Two students were cited for disorderly conduct in the building and two outside during a fire evacuation.

Two female students were arrested at the school entrance when metal detectors found a razor on one and a nail file on the other - items prohibited under the district weapons policy.

More arrests are pending for two small fires that were set in lockers. The school was evacuated at 11 a.m. and again a short time later.

Attendance was down to between 40 and 50 percent yesterday, said Ozzie Wright, acting co-principal. It's usually at 75 percent.

District officials hope they can calm the school today so 11th graders can take the Pennsylvania System of School Assessment, the high-stakes test that determines whether schools meet federal achievement targets.

Testing will continue through next week.

Wright - who previously headed a school district military academy - said he and co-principal Ernest Caldwell were meeting with small groups of students and reaching out to teachers for suggestions. They also plan to have a parents' meeting.

Students are upset about the loss of James and the lack of activities and clubs at the school, he said.

Councilwoman Jannie Blackwell planned to tour the school today, in part to bring attention to the need for such programs.

"We want to talk about making West Philadelphia a pilot for programs, everything from job training to after school to involving universities," she said.

Students and parents echoed her sentiments.

Ninth grader Saliyma Whiting, 14, said she and her friends wanted to organize a group to give students more activities.

"The more activities, the less violence there is," Whiting said yesterday. "We want attention, so we're going to get attention in a positive way. We want to start a little group for kids who still want to get an education."

Annette Blake, whose daughter Javonna is in ninth grade, said she was upset that James had become a "scapegoat."

"He actually turned the school around," she said, noting that there were more fires at the school a few years ago.

Some are optimistic about Wright's ability to improve the school.

"We really like him," said Denise Shank, 15, who is in the high school's JROTC program. "It seems like he can turn stuff around, but the kids are not giving him a chance."

Wright and Caldwell plan to start a mentoring program for younger students with upperclassmen from the JROTC program.

They also hope to upgrade the school camera security system for better surveillance. Five school police officers have been added to the 10 stationed inside the school, and six additional city police officers are helping outside.

"What we all would like to see is that the staff as well as the students feel as safe as possible," Wright said. "We just want to get this school back on track."

Students have set fires at other schools, sometimes in protest. Olney High School, a historically troubled school, was plagued by a rash of 16 suspicious fires in the first half of the 1999-2000 school year.

District officials said they suspected the media attention may be causing some of the acting out at West Philadelphia.

"But there's no excuse for the lack of self-control. There's no excuse for lighting a fire," said Vallas, who spent time at West Philadelphia yesterday.

Wright will get the school under control, he said.

Pat O'Hara, a teacher and union representative at the school, was also optimistic.

"It's just going to take time," he said. "We're faced with putting Humpty Dumpty back together."