Mayor Bill de Blasio has said he is going to get rid of all of the classroom trailers across the city, but some of the trailers are being repurposed for pre-k classes. Our education reporter, Lindsey Christ, has more.

Six weeks ago, this was an empty lot in Long Island City. Now, it's filled with trailers — trailers filled with four-year-olds.

It's one of four sites in Queens where the city's Department of Education has put up 16 temporary classrooms over the past few weeks.

That's part of an effort to place 288 pre-kindergarten seats in neighborhoods where the public schools have no more space. But these decades-old trailers had been designated for the dump before the city relocated and reconstructed them.

"It is very frustrating," said Assemblywoman Catherine Nolan. "We worked hard to get them removed from some of the other schools in the district, and now they've resurfaced - retro-fitted, old trailers. And obviously, not an ideal situation. But again, parents down here were so happy to accept it, because they so desperately needed pre-k seats."

The trailers are still under construction at PS 7 in Elmhurst. At PS 28 in Corona, the playground was ripped up to make way for them. 

A few blocks away at PS 16, the trailers occupy a lot that was used for recess. Older students miss their schoolyard. 

"We just get bored inside sometimes," said fifth grader Marcos Alvaravo. "We just play inside."

The de Blasio administration pledged two-and-a-half years ago to remove all of the city's 350 classroom trailers within five years. Now, halfway to that deadline, just 82 trailers have been removed. 

Nearly 7,000 elementary and middle school students still attend classes in trailers, many of which are falling apart, with moldy walls and rotting floors.

When asked if there are any specific plans for when these trailers will be retired, education officials declined to give a date, saying only that they are committed to removing all of the trailers across the city.

Parents say they are happy to have the pre-k seats but will push for permanent classrooms.

"Our hope is, that once these new schools are built that we can start to phase out some of those some short-term solutions," said Kadie Black with the Gantry Parent Association in Long Island City.

But classroom trailers have always been billed as a short-term solution. Decades later, most remain in use.