After a long fight with Albany and some last-minute concerns about safety, Universal Pre-K launched in New York City today with over 50,000 students attending full-day Pre-K, more than double the attendance last year. In just nine months, Mayor de Blasio has made good on one of the cornerstones of his campaign.

“We are building a new and better foundation for our children and our city. This is a monumental moment in the lives of tens of thousands of children and their families....We fought and we pushed so hard because we believed our families could not and should not wait. And today, the dream of Pre-K for All becomes a reality in New York City,” de Blasio said in a statement.

As part of a five-borough tour of Pre-K classrooms, de Blasio started the day in Brooklyn, where he was joined by high-ranking members of the city council, as well as schools chancellor Farina and his wife, Chirlane McCray.

But as late as last week, there were significant concerns about the safety of the classrooms, as well as some last-minute cancellations of some of the programs. Comptroller Scott Stringer sounded the alarm, saying that the mayor's office had not yet sent him contracts for review, and that, as a result, his office was unable to perform safety checks.

“Universal Pre-K holds the promise of transforming our City’s educational process, which is why we have to get it right,” Stringer said then in a statement. “But we cannot sacrifice safety in the name of expediency.”

This led to some serious horn-locking between Stringer and de Blasio, with de Blasio saying at a press conference that he didn't know why “any public official would want to leave parents with the misimpression that there’s a danger when there isn’t a danger."

Still, only a week before today's launch, one of the largest Pre-K classrooms remained unfinished. And on Tuesday, the city abruptly announced that forty-five Pre-K programs across the city would either not open on time or not at all this year, leaving parents in the lurch and scrambling to find seats in the already crowded classrooms.

The $300 million in new funding will keep the fifty-thousand children in school for over six hours, theoretically giving them the advantage de Blasio sees as vital to raising test scores and improving the state of education overall in the largest school district in the country.