PROVIDENCE — Del Sesto High School will get a third principal and an outside intervention expert to help turn around the troubled school, Deputy Supt. Frances Gallo said yesterday.

Although she acknowledged that the building needs extra help, Gallo repeatedly denied that Del Sesto, which houses a high school and a middle school, was a school in crisis.

“This is an urban high school, and it’s filled with kids,” she said. “It will feel disorderly. We need to get down to earth. When I’m there, I don’t see disorder. Is there groping going on in the building? Probably yes. Is it appropriate? No.” The district, she said, needs to give teachers the skills they need to cope with this sort of behavior.

Gallo said that the district is adding another principal to work with Assistant Principal John Craig, who oversees Del Sesto High School. In addition, the district has hired Donald Pellegrino, an outside intervention expert, to help the four principals figure out how to work together as a team. In addition to Craig, the complex has a middle school principal and a principal in charge of the entire building.

During Tuesday’s School Board meeting, several middle school teachers complained that the school was out of control. They said Del Sesto High School students were unruly and disruptive, interrupting classes, talking back to teachers and bothering middle school girls. One middle school teacher, Jeremy Senser, said he saw a girl being groped by a male classmate, while other teenagers watched. When he asked the couple to break it up, the girl swore at him and refused to give him her name.

These teachers say that it simply isn’t appropriate to house older teenagers with younger ones. Del Sesto began as a middle school and added ninth graders last year and tenth graders this year. Elementary school students are taught in a separate building on the same North End campus.

Although teachers said the problem has been building for some time, Gallo said the school had a smooth opening.

“Gradually,” she said, “the kids got comfortable. … The teachers started slipping.” They stayed inside their classrooms during passing time. The principal spent more time in his office, filling in for clerical staff or dealing with crises. Before you know it, Gallo said, things started to happen.

“There were a variety of incidents across our schools, and we acted on them,” she said. “We are retraining our principals and assistant principals on how to conduct an investigation.”

Pellegrino, a former administrator from Massachusetts, was hired three weeks ago to help all the high school principals develop their leadership skills. Gallo said the district asked him to evaluate the situation at Del Sesto, and, after observing the school, Pellegrino recommended putting additional staff in the building.

“We are adding another principal for the remainder of the year who can work with Mr.Craig in conjunction with Mr. Pellegrino,” Gallo said. “We want to build a culture that offers a safe and orderly learning environment.”

Gallo denied that the district failed to act on the problem in a timely manner.

“On Oct. 27, the faculty met with the union,” she said. “The following Friday, the union brought it to our attention and we began to create a plan.”

On Tuesday, the director of middle schools, Denise Carpenter, told teachers about the additional support that the district had planned. Carpenter met with members of the School Improvement Team and the union.

Gallo said that part of the problem arises from the understandable tension between middle school teachers, who felt the building was theirs, and the high school teachers, who began arriving last year.

At least one high school teacher said that Del Sesto has been unfairly maligned by the school’s middle school colleagues. The teacher, who asked to remain nameless, said the middle school students are just as unruly as the older ones.

“We were thrown into the building last year with no books and no supplies,” the teacher said. “The middle school teachers resent us being here. The school just doesn’t jell.”

Both groups of teachers agree on one thing: that the high school doesn’t belong in a middle school building.

Asked whether the district would consider moving the high school students to the new building under construction on Adelaide Avenue, Gallo said, “all of this is on the table.”

Del Sesto has had a troubled past. The high school began the 2005 school year without adequate textbooks and supplies. After teachers complained that the school was rudderless, Supt. Donnie Evans appointed Craig to put the school back together.

In March, students staged a sit-in after Craig was transferred, something the principal had originally requested. But Evans restored Craig after listening to the outpouring of support from students and faculty.