For one school in the Bronx that meant a brand new location.
P.S. 51 was forced to move a few miles from Bedford Park to East Tremont after tests discovered a potentially hazardous chemical inside.
Now that discovery is prompting the city to examine other schools for similar problems.
Teachers Union President Michael Mulgrew on Tuesday offered his support to the relocated teachers of P.S. 51.
"The majority of them were here all last week, way before they were supposed to report, making sure that this building was ready for the children when they came in on Thursday," Mulgrew said.
A former Catholic school, more than two miles from the previous location, has quickly been converted to the new home of P.S. 51.
"So, it's been a huge move, but we're here and we're ready to go to work," Eileen Bernstein, a P.S. 51teacher.
P.S. 51 had occupied the space in Bedford Park for some 20 years.
It was once a lighting factory, among the many spaces leased by the Department of Education for school use.
The need to move P.S. 51 leaves behind the question: Why did it take so long to figure out that a former factory may not be the healthiest place to run a school?
Former P.S. 51 teacher Gerry Powell says she and other colleagues always thought the building should be tested.
"Because it's such a small school, and we were also getting a strange smell at one time, it's another reason we thought so," Powell said.
The Health Department says T.C.E. does not have lasting effects on the body.
P.S. 51 parents and staff gathered for a meeting last month, with Schools Chancellor Dennis Walcott.
The D.O.E. has stepped up its efforts at environmental testing, especially at 31 leased sites that never had an environmental audit.
"We still have 31 buildings that are lease sites that have never had an environmental audit, and I know the Department of Ed said they're going to check them, and we're glad that's happening, but it's sad it took this to make that happen," Mulgrew said.
The new location is about two miles from the old school building.
The Department of Education says its more than 200 students will be eligible for busing.