Faced with a surge in shootings at the city’s public housing, Mayor Bill de Blasio on Tuesday detailed a $210 million to plan to improve safety at the buildings, which more than 400,000 people call home.

Even as crime has dropped slightly citywide, shootings have gone up 31 percent so far this year in New York City Housing Authority buildings. An outsized portion of that spike has been centered in 15 troublesome projects, which are responsible for 20 percent of the violent crime this year across 334 NYCHA developments.

“We are making investments in our public housing — investments that should have been made long ago,” de Blasio said at an East Harlem development. “You know the phrase, ‘He who hesitates is lost’? We are not interested in hesitation.”

De Blasio said the safety measures would start in the 15 projects, which include Brooklyn’s Boulevard Houses, where a 6-year-old boy was stabbed to death last month.

The money — much of which was allocated in the budget agreement announced last month — will go in part to funding a program that will train 200 civilians to handle New York Police Department desk jobs, allowing 200 more police officers to go on the beat in public housing. The money will also be used to repair broken security doors, rehabilitate aging buildings, keep community centers open later and install new lighting in previously dim — and often dangerous — sections of NYCHA property.

Previously, de Blasio announced that the city would pay the $122 million NYCHA owed the NYPD for security. The mayor, who was joined by Public Advocate Letitia James and City Council Speaker Melissa Mark-Viverito among other elected officials at Tuesday’s news conference, has made NYCHA improvements a priority during his first year in office.

He has relentlessly criticized predecessor Michael Bloomberg for ignoring public housing, which is home to more people than all of Cleveland or New Orleans. But in the wake of the high-profile Boulevard Houses stabbing, he acknowledged that his own administration had been too slow to address security concerns.

“The buck stops with me,” he said in June as he pledged that all NYCHA buildings would have security cameras by year’s end. At the time of the stabbing, nearly 60 percent of public housing buildings did not have cameras.

(AP)