The unarmed security guard killed by Midtown maniac Shane Tamura was the dad of a 6-year-old boy whose birthday is this weekend — and doesn’t know yet that his father is dead.

Beloved family man and “New York hero” Aland Etienne, 46, was identified as among four innocent victims killed by Tamura as the gunman entered 345 Park Ave. in Manhattan on Monday evening in a rampage apparently targeting NFL headquarters.

Loved ones and colleagues revealed that the native Haitian heartbreakingly left behind a young son who hasn’t learned about the tragedy.

The boy’s 7th birthday is Saturday, they said.

“He was more than a brother — he was a father, a son, and a light in our lives,” wrote Etienne’s brother Gathmand Etienne in a Facebook remembrance.

“Our hearts are shattered, and we’re asking for your prayers and strength as we navigate this painful time.”

Etienne was fatally shot as he crouched behind a desk to take cover as Tamura sprayed the building’s lobby with bullets, police said. He was unarmed, as are the thousands of security officers across the city, a union rep said.

The security guard lived in Canarsie, Brooklyn, where his girlfriend declined to talk to The Post until his family arrived from Florida.

“We’re too upset to talk right now, we’ll talk later,” said a man, who identified himself as Etienne’s brother, over the phone.

Etienne had five brothers, a sister and an older daughter, in addition to his young son, sources said.

He left his friendly mark in the Park Avenue building where he worked.

Jubel Ahman, 30, who works at a kiosk in the building’s lobby, told The Post he affectionately called Etienne “Eli” and recalled his friend’s morning greetings.

“Every morning when he passed, he’d wave and say, ‘Good morning, see you later,’ ” Ahman said. “He came here regularly to buy lotto.

“Sometimes he won like $500, $1,000 – not too much. He used to tell me one day he was going to be a millionaire, that’s why he played so often.”

Etienne would finish his shifts, take a 45-minute nap and then head to his second security guard job in Midtown, Ahman said.

The kiosk worker said he heard the shots that took his friend’s life.

“Yesterday he never came,” Ahman said. “If he missed a day, the next day he’d come and told he was busy, so I thought he was busy yesterday.

“I wish he would have come and we could talk one last time.”

Manny Pastreich, president of the 32BJ SEIU union for security workers, said Etienne’s death speaks to the sacrifice of security officers who risk their lives every day.

“Every time a security officer puts on their uniform, they put their lives on the line,” he said in a statement. “Their contributions to our city are essential, though often unappreciated.

“Aland Etienne is a New York hero. We will remember him as such.”

The union represents roughly 90,000 workers, including security guards.

How the shooting unfolded

• Reports of the shooting at 345 Park Ave. start coming in around 6:28 p.m.
• Shane Tamura, 27, is seen getting out of a black BMW between 51st and 52nd streets with an M4 rifle.
• He enters the lobby and turns right, where he shoots police officer Didarul Islam, 36, dead.
• Tamura guns down a woman cowering behind a pillar in the lobby, sprays more bullets and walks toward the elevator bank — where he shoots dead a security guard crouching at his desk.
• One more man reports being shot and injured in the lobby. He was in critical but stable condition.
• The gunman allows a woman to walk out of the elevators unharmed before heading up to the 33rd floor, where building owner Rudin Properties’ offices are located, “and begins to walk the floor, firing as he traveled.”
• One woman is shot and killed on that floor before Tamura shoots himself in the chest.
• It’s unclear how long the mayhem lasted. Police Commissioner Jessica Tisch posted on X at 7:52 p.m.: “The scene has been contained and the lone shooter has been neutralized.”

The shocking mass shooting by Tamura, 27, remains under investigation by the NYPD. 

But details trickling from the terrifying spree have so far provided a portrait of a troubled gunman, a former high school football star who left a three-page suicide note blaming football for his perceived struggle with the brain injury CTE, or chronic traumatic encephalopathy.

Tamura apparently blamed and targeted the NFL, but evidently took the wrong elevator while trying to get to the league’s headquarters in the Park Avenue office highrise, Mayor Eric Adams said.

The Las Vegas native, who drove cross-country with a high-powered rifle, first gunned down NYPD Officer Didarul Islam when he entered the building, officials said.

He then fatally shot Blackstone exec Wesley LePatner — who was hiding behind a pillar in the building’s lobby — and wounded an NFL executive.

Etienne, who hid behind a desk, was fatally shot as Tamura marched to the building’s elevators, officials said.

The shooter then took the elevator up to the 33rd floor, home to building owner Rudin Management, where he shot the company’s employee Julia Hyman, according to officials.

Tamura then turned the gun on himself, fatally firing a bullet into his chest.

“Please study brain for CTE,” his suicide note read.