Everyone — from the principal to pre-kindergartners — faced a lot of work. The school had three years to improve, or face possible takeover by the state Department of Elementary and Secondary Education.

“It was very hard on us,” said Stacy Phelan, the school’s program specialist, and a former English teacher. “We all felt like we had done something wrong, even though our kids were really trying.”

Now things are looking up for the school in West Lynn, built in 1938 by the federal Works Progress Administration and named for a congressman.

When this year’s MCAS scores were released on Sept. 19, Connery was among the top 10 schools in Massachusetts posting the largest two-year gains in student achievement. English scores increased 11 percentage points and math went up 15 percentage points, according to state data. It was the second year in a row in which Connery placed in the top 10 of most improved schools.

The results made principal Mary Dill, who has a doctorate in education, proud of her young charges and staff.

“Connery School has a school culture and working environment where student learning and engagement is our focus,” said Dill, a veteran Lynn educator assigned to Connery to launch the turnaround plan.

Other most-improved schools include Charlotte M. Murkland Elementary School in Lowell and Lynn’s E.J. Harrington Elementary School. Low-performing schools must submit redesign plans to the state, outlining clear goals for improvement. Progress must be made for three consecutive years before a school is no longer designated as Level 4, or lowest performing.

“This is a big year for both of our schools,” said Susan Rowe, deputy superintendent for curriculum in the Lynn public schools. “ It’s hard to make gains three or four years in a row. . . . We’re going to keep going, working as we have.”

In June, the Connery was one of nine Massachusetts schools, along with four in Lawrence and one in Salem, to share $13.7 million in federal grant money, awarded by the state, to help fund turnaround plans.

“Business as usual was not going to get them better results,” said state Education Commissioner Mitchell Chester. “In the schools that have been improving, there has been a comprehensive approach to reorganizing around a more effective program.”

Chester said the most effective plans institute aggressive reform. “Most of them have substantial turnover and replacement of previous staff,” he said. “This is not for the faint-hearted. It requires a willingness to rethink how a school is organized.”

At the Connery, the principal was replaced, as required by the state. Most of the 44 teachers transferred to other schools or retired. The turnaround plan addressed academic, emotional, and social needs of the students.

Of Connery’s 594 students, 94 percent are low-income, and 77 percent live in homes where English is not the first language.

At least 30 cultures are represented, but the majority are Hispanic. Many families struggle with poverty, violence, and homelessness, Dill said.

“It isn’t just teaching that contributes to the success of a child,” Dill said during an interview in her office. “It’s making sure that all the child’s needs are met. . . . Our focus is on the whole child.”

Connery has two social workers and a school-based health clinic run by the Lynn Community Health Center. The Forsyth Institute of Cambridge also sends dentists to the school twice a year for check-ups.

“What we’ve learned is, you can have the best instruction possible, but if a child can’t learn, either because of illness, or something is wrong at home, you won’t make the progress we need,” Rowe said.

The swift pace of academic change tested teachers and students. The state requires teachers at low-performing schools to take professional development courses, which they are paid to attend during the summer and school year. The courses are titled “Teaching the English Language Learner” and “The Trauma Sensitive Classroom.”

Teachers in the same grade level share common planning time, to review curriculum and teaching practices. Teachers work in teams, to collaborate in increasing student learning.

Most taught summer school, attended by 260 children in July and August. Saturday school, offering three hours of remedial help, will start in January.