Two young people plunged from city buildings Tuesday, leaving one dead and the other critically injured, cops said.

The first tragedy occurred at around 6:40 a.m. when an 18-year-old woman leaped from an apartment building on East 29th Street near Park Avenue, authorities said.

The woman, who wasn’t identified, was impaled on a street-level fence and was pronounced dead at the scene.

About two hours later, a 22-year-old man jumped from the rooftop of a six-story building at 2537 Valentine Ave. in The Bronx, cops said.

The man, who also wasn’t identified, was in critical condition at St. Barnabas Hospital, police said