The city has begun to process of shutting down more than a dozen low-performing schools in June.

Chancellor Carmen Fariña said Monday that the city education department will close 14 schools and merge five others with another school in the same building. A 20th school will lose its middle school grades and serve only high school students.

Mayor Bill de Blasio has said he only believes in closing struggling schools as a last resort.

But Monday's announcement represents the largest group of schools to be closed in a single year since he took office.

Most of the schools are in the mayor's so-called renewal program, a controversial $600 million effort to give troubled schools extra help and three years to turn things around.

Now, time is up. But the chancellor said just 21 schools — less than a quarter of the original group — are successful enough to graduate out of the initiative. 46 schools will continue in the renewal program, with extra help and oversight.

"The schools that will be in Year Four are schools that we feel need that extra year to show that next level of success," Fariña said.

Five of the schools are not part of the program, including Urban Assembly School for Wildlife Conservation in the Bronx. In September, a student, 15-year-old Matthew McCree, was stabbed to death in a classroom in that school.

"Every time I go, there are other things that come to my attention," Fariña said. "First and foremost, that students are asking to leave and that the enrollment for next year was projected as first choice; no more than five children — students were applying."

The closures mean 4,500 students and 400 teachers will need to find a new school by September. The education department said it will have counselors available, and, for the first time, the administration plans to open several new schools to replace those being closed.

Fariña said the education department's decision came after thorough review and discussions.

Ultimately, she said it was the best step to help give kids the educations they deserve.

"In a city of 1,600-plus schools, there are always going to be struggling schools. Just the law of averages. It is how we rise to the occasion and how we handle these schools and we support them and how we hold ourselves accountable that is the real test of an educator," Fariña said.

Fariña also announced that nearly half of the remaining renewal schools will now become so-called Rise Schools at the end of the school year because they surpassed targeted benchmarks.

No new schools will be added to the renewal program, which critics say that suggests the initiative was not effective enough. The chancellor said other reforms are now in-place to help struggling schools, like more literacy coaches.

The city is required to hold hearings before an education panel, which is controlled by the mayor, votes on the closures. It is a process that will happen over the next two months.

McCree's mother, Louna Dennis, said she is against the closing of the Urban Assembly School for Wildlife Conservation because it does not address what she said is a larger problem.

"The issue is the administration that they have. They're going to close the school now and they're going to move them to a different school," Dennis said. "The problem still exists. They're untrained, they don't know how to deal with kids."

"What are they trying to do, cover up their tracks by closing the school?" Dennis added. "What, they're trying to sweep evidence under the rug?"

"This family calls upon the mayor to fire the chancellor. That's what has to be done," Sanford Rubenstein, the family's attorney, said outside the school. "Closing this school is not enough."