The savage Saturday slayings of four homeless men in Chinatown come as the city’s homeless population is at its highest point since the Great Depression — and shelters are bursting at the seams.

The number of people sleeping on the street is up 15% from 10 years ago, to 3,588, according to an April report from the Coalition for the Homeless, and 7% since January 2014, when Mayor Bill de Blasio took office.

The number of single adults sleeping in shelters has ballooned by 150% since 2009, hitting 18,212 in February.

And the overall shelter population reached an all-time high in January, with 63,839 men, women and children sleeping in homeless facilities each night. The shelter population has gone up 20% since 2014, the year de Blasio took office.

Meanwhile, spending on homeless services has more than doubled since de Blasio was elected in November 2013, reaching $3.2 billion this year.

In the hours after the Saturday bloodbath, the Coalition called on city and state officials “to build enough deeply subsidized housing for homeless New Yorkers to match the scale of the need in order to prevent such a tragedy from ever happening again.”

The Coalition blasted Hizzoner’s homeless initiatives in its April report.

The group called his goal to move 2,500 people out of shelters by 2022 “embarrassingly unambitious” and said his focus on luxury housing as opposed to affordable apartments has exacerbated the problem.

“Mayor de Blasio’s hollow plan to address the crisis, Turning the Tide on Homelessness, has floundered, failing entirely to live up to its title,” the Coalition wrote.

The group also slammed Gov. Andrew Cuomo’s policies, giving him “multiple failing grades on housing vouchers, homelessness prevention, and systematic cost-shifting practices that unduly burden the City.”

First lady Chirlane McCray’s $1 billion Thrive initiative has also come under fire for failing the city’s mentally ill homeless population.

A $2 million Thrive “triage center” where cops and clinicians work together to help the homeless and mentally ill, saw only 885 patients in 2 ¹/₂ years.

Meanwhile, the NYPD received nearly 180,000 calls to assist emotionally disturbed people in 2018, up from 145,000 in 2015.

“The city and the mayor should be held accountable for the loss of these innocent lives,” said Karlin Chan, a member of Chinatown’s Community Board 3.

“He’s spent one-point-whatever billion on Thrive, and they couldn’t even say how many people they’ve helped,” Chan said, referring to revelations earlier this year that there was no system to track the program’s progress.

Mitchell Moss, professor of urban policy at NYU and former advisor to former Mayor Michael Bloomberg during his first mayoral campaign said it was “shocking” that McCray has “been given an enormous amount of money to deal with mental health to absolutely no impact.”

“When the Comptroller and the public advocate – who never agree – both say that Thrive has been a massive diversion of municipal funds with no clear impact then there are some real questions to ask – how long can we tolerate this waste of public funds?” Moss said. “They claim they have trained people on mental health and raised awareness but have failed to take care of the actual problem.”

Chinatown residents say they have noticed a big increase in the homeless population in recent years — further bloated by the city’s revolving door policies.

“Let’s say a person seems to be menacing people, the police will take them away, but if they haven’t hurt anyone, they’ll clean them up, give them a shower and they’re right back out in the streets in 7 or 8 hours,” Chan said.

He noted that the long rap sheet of Rodriguez “Randy” Santos, a local homeless man who police say committed the four murders, reflects that trend.

“This guy had 14 priors. He was just arrested four or five months ago for an assault,” he said.

De Blasio has softened the city’s approach to policing in favor of better community relations, but some say the shift — which includes virtually eliminating stop and frisk — has allowed criminals and vagrants to thrive.

“With de Blasio, it’s their right if they want to sleep on the street. Meanwhile, people are getting killed and hurt. You can’t even walk down the sidewalk,” said Little Italy resident Josephine Bray.

Wellington Chen, executive director of the Chinatown Business Improvement District, noted that “the police have actually said to us their hands are quite tied.

“It’s not like in the old days where they could say, come in with me to the precinct house,” Chen said. “They have the right to stay on the street, and that’s unfortunate, because it renders the police powerless, the property owners powerless and the homeless outreach powerless.”

Additional reporting by Paula Froelich