The West Indian Day parade was once again marred by violence Monday, leaving a legal aide for Gov. Cuomo in critical condition with a gunshot wound, two others with shooting injuries and a fourth man dead in a stabbing.

Cuomo identified his wounded staffer as Carey Gabay, a first deputy general counsel at the Empire State Development Corporation. Gabay was walking with his brother near the Brooklyn parade route at 3:40 a.m. when he was caught in the crossfire between two gangs, according to police officials.

A bullet struck Gabay, 43, in the head. Cuomo said Gabay, a Harvard-educated lawyer who had worked as an assistant counsel to the governor.

"I'm the governor of the state of New York, and there's not a thing I can do," Cuomo told reporters after he visited his staffer's family at Kings County Hospital. "There's not a thing I can say, and there's nothing I can do. And sometimes it just hurts."

No arrests have made been, police said. The shooting was one of several outbursts of violence in the neighborhoods surrounding the parade, which included the stabbing death of a 24-year-old man at 2 a.m. near Grand Army Plaza.

Bloodshed before or after the West Indian Day celebration has become a sadly familiar part of the parade routine. Last year, a recent parolee opened fire into a crowd of revelers, killing one man and wounding several others. And in 2013, a 1-year-old boy sitting in his stroller was killed by a bullet meant for his father.

Mayor de Blasio and Police Commissioner Bill Bratton dismissed talk of scuttling the preparade festivities -- which center on a surreal midnight march known as J'Ouvert -- and said the NYPD was working with local leaders to make the event safer. There was a heavy police presence along the route, and several NYPD helicopters hovered overhead.

The parade went on as scheduled and drew hundreds of thousands of people to the stretch along Eastern Parkway. Throbbing basslines pulsated along the route, propelling outlandishly clad revelers to dance and those along the sidelines to bob their heads as they ate indigenous foods.

"This is our heritage. It means so much to me to see all these colors and music," said Alicia Jackson of Brooklyn. "It's one of my favorite days of the year."

Politicians dotted the route, with de Blasio and his wife, Chirlane McCray, who is of Caribbean descent, drawing cheers as they waved flags and periodically dashed to the sidelines to shake hands and pose for selfies.

But the parade was also the latest venue for New York's most high-profile political feud. The march and an official preparade breakfast were the first public events since July in which Cuomo and de Blasio, who are locked in a simmering dispute, were both supposed to attend.

But their paths never crossed. Cuomo left the breakfast about 10 minutes before de Blasio arrived, and the two men, both Democrats, marched separately.

At the breakfast, Cuomo was asked if he planned to speak to the mayor. The governor responded by asking, "Is he here?" and when told no, Cuomo glared and bluntly said, "There's your answer."

Hours after the parade, Cuomo and several other elected officials flew to Puerto Rico to offer advice to the island government grappling with a debt crisis. De Blasio was not invited.