This is part one of a two-part series.
On the fourth floor of a fortress-like building in lower Manhattan housing four public high schools, more than 500 students cram into classes such as calculus and agriculture. They operate 3-D printers and tend herbs in a hydroponic farm.
In the basement, about 500 students at another high school prepare for emergency medicine careers with a new ambulance simulator. They can graduate with associate degrees and participate in activities that include cursive club and lip sync battles…