An army of cops, hundreds of floodlights and big promises from the mayor weren’t enough to stop murder and mayhem at Monday’s J’Ouvert festival in Brooklyn — and fed-up revelers said it’s time to scrap the whole thing.

Even Mayor Bill de Blasio, who last week vowed the “safest J’Ouvert ever,” said pulling the plug on the violence-plagued annual celebration was “on the table.”

Two bystanders were killed and two more wounded in three shootings starting at around 3:45 a.m., with large crowds gathered on the streets of Crown Heights.

In both slayings, bullets flew just feet from dozens of cops standing watch under blazing light towers, with one police source likening the situation to “being shot in broad daylight in front of hundreds of people.”

The gunfire ignited chaos as dozens of people stampeded for safety, hurtling themselves over metal barricades and hiding behind cars and garbage cans.

In addition to the shootings, a man and a woman suffered nonfatal stab wounds in separate attacks, cops said.

No arrests had been made by early evening.

This year marked the first time the NYPD required organizers to get a permit for J’Ouvert, which Police Commissioner Bill Bratton has called “probably the most problematic event in the city.”

Asked if it was time to call off the dangerous predawn revelry ahead of Brooklyn’s West Indian Day Parade, de Blasio said he was planning a “full review” of this year’s deadly disorder.

“Just making a broad, strategic statement, all options are on the table. But we’re going to look at the whole situation with the NYPD and community,” he said.

City Councilman Brad Lander (D-Brooklyn) said, “It seems, sadly, pretty clear that big changes are needed.”

“I’m open to canceling it next year,” he added.

Gov. Andrew Cuomo, whose aide Carey Gabay was fatally hit by crossfire at J’Ouvert last year, was infuriated by the latest bloodshed.

“We had more violence and more death last night, and I think, in some ways, the cruelest situation is when you can predict the violence and you can predict the death, and you still can’t do anything about it, and I hope this is a wake-up call,” Cuomo said.

“Carey Gabey should not have died in vain . . . The violence last night, we need to get the message.”

A neighbor of slaying victim Tiarah Poyau, 22, echoed calls to end the event, meant to be a celebration of West Indian culture.

“They need to close the festival. This is not the first year someone got killed,” said Anna Jackson, 57.

“Police add more security, but that’s not going to stop anybody.”

Even loyal paradegoers said J’Ouvert had run its course.

“It makes me sad to say it, but they just need to cancel it,” said Tracy Walker, 42, of Flatbush.

“Every year, more people are shot — or killed.”

Samuel Benoit Jr., 44, of Queensbridge, Queens, lamented that “people don’t know how to have fun without hurting people.”

“If they can’t stop it, they should say, ‘No more J’Ouvert,’ ” he said.

“I love celebrating my culture, but with the murders, it’s just not worth it.”

Hours after the J’Ouvert bloodshed, the West Indian Day Parade went off without a hitch, with thousands of revelers and performers dancing to Caribbean beats as a procession of floats headed along Eastern Parkway.

Ruben Guillandeaux, 28, a free-agent pro basketball player, said he was raised on Eastern Parkway along the parade route and had “seen almost every parade since I grew up here.”

“J’Ouvert should have been canceled years ago. It puts officers at risk. It puts people in the situation where the police are afraid to police. You got drugs and alcohol. People come out from not-so-nice areas,” he said.

“You don’t need a celebration at nighttime. The parade is enough.”

The first explosion of gunfire erupted around 3:45 a.m. near Empire Boulevard and Flatbush Avenue, NYPD Assistant Chief Patrick Conry said.

Tyreke Borel, 17, was shot in the chest and died at Kings County Hospital, sources said, while Margaret Peters, 72, was injured by a bullet that hit her in the forearm as she sat on a bench.

Conry said recovered shell casings suggested a gun battle, adding that cops believed “one if not both of those individuals are unintended targets.”

The second shooting took place around 4:15 a.m. at Empire Boulevard and Franklin Avenue, where Poyau was fatally shot in the eye. She, too, was believed to have been hit by a stray bullet, Conry said.

In the third incident, an unidentified 20-year-old man was shot in the leg near Rogers and Clarkson avenues around 6:45 a.m. His injury was not life-threatening.

The city planned for months to keep the festival safe — an effort that included posting fliers that warned: “This community will no longer tolerate violence. Do not shoot anyone. Do not stab anyone.”

Brooklyn Borough President Eric Adams, a former NYPD cop, rejected any effort to shut down J’Ouvert or the parade.

“We need to be clear: New York City and NYPD do not surrender to violence, violence surrenders to us,” he said.

Additional reporting by Kevin Fasick, Jennifer Bain and Daniel Prendergast