Twas the night before Christmas, when all thro’ the house, not a creature was stirring . . .

. . . except two guys on the roof of the Harry Winston jewelry store in the Gold Coast.

It was Christmas Eve 2007, and one of the city’s most ambitious, potentially lucrative heists was about to unfold.

It was like something out of “Ocean’s Eleven” one detective recalled — except neither the cops nor robbers won.

And it’s all been kept a secret — until now.

Five weeks before the break-in, the store held its grand opening  — an invite-only affair for Chicago’s muckety mucks.

One particular gem, nestled behind thick glass, drew oohs, ahhs and ink in both Chicago dailies.

The Target

The Lesotho One — a stone with a well-known pedigree.

At 71.73 carats, it was the largest of 18 gems cut from a single rough stone that made headlines when discovered in 1967 in the small African nation of Lesotho.

One of its sister stones — the smaller Lesotho Three — was given by Aristotle Onassis to Jacqueline Kennedy as an engagement ring.

Police believe the Lesotho One — with an estimated worth of more than $5 million — was the burglars’ target; however, other gems in the store represented untold millions.

During the day, four off-duty or retired Chicago Police officers guarded the store.

But at night, there was none.

The name Harry Winston is synonymous with the rich and famous. The company has bejeweled celebrities on Oscar night for decades.

The Lesotho One, one of the world's largest diamonds, lies in a case at The Wedding Salon bridal show April 26, 2005 in New York City. | Getty Images

The Lesotho One, one of the world’s largest diamonds, lies in a case at The Wedding Salon bridal show April 26, 2005, in New York City. | Getty Images

The Heist

The robbers gained access to the roof of a neighboring building and jumped from roof to roof until they were on top of Harry Winston, 55 E. Oak.

Three stories below, a getaway driver was circling the block — all the while, listening to a police scanner, detectives suspect.

It was not a White Christmas that year, records show. It was overcast and cold, about 26 degrees.

About 9 p.m., the men cut a hole through a hatch on the building’s roof.

Before lowering themselves out of the freezing air, they attached alligator clips — metal clamps with serrated jaws — to an electrical box to bypass an alarm.

At the bottom of the ladder, they punched a hole through a wall that led to a stairwell and descended to the second floor, where they made their way to a very specific spot.

Below was the safe room.

The men used a drill with a bit over a foot long, a saw and a sledge hammer to break through cinder block, wire mesh, drywall and wood.

It was about 10 p.m. They’d been in the store for about an hour and had finally created a hole into the store’s inner most sanctum.

Then, suddenly, they bailed — most likely due to a brief message over the two-way radio from their driver: the cops are coming.

Alvin Greenup Sr. was the first officer on the scene.

“I saw a guy on the fire escape on the side of the building, but he jumped down and took off before I could get to him,” said Greenup, who’s still a Chicago cop.

Greenup, 43 at the time, came within about 25 feet of the man.

“I chased the guy for about half a block through the gangway and another gangway, but he jumped into a waiting car on Walton . . . they left in a powerful hurry,” he said.

Greenup recalls seeing only one man. It’s possible another burglar had made his way to the waiting car before Greenup arrived, he said.

Surveillance camera footage from nearby buildings did not capture the license plate of the black Pontiac Grand Prix getaway car.

The Investigation 

Hours before the men entered the store, an alarm briefly drew the attention of Harry Winston security, but it was dismissed as a recurring bug in a newly installed system.

About 10 p.m., though, another alarm was tripped. This time, a security agent for Harry Winston in Toronto — the company was based in Canada at the time — saw the burglars on a live video feed and notified the Chicago Police Department.

Both men were white and appeared to be in their 20s. One wore blue jeans and a dark puffy coat; the other wore black pants and a black hoodie.

The case was assigned to Det. Blase Foria.

“It was one of the most intriguing and frustrating cases I’ve ever worked,” recalled Foria, who retired in 2016 and sat down with the Sun-Times recently to fill in the gaps of a police report obtained by the Sun-Times.

Foria arrived at the store pre-dawn on Christmas Day. A lack of footprints in the debris on the safe room floor confirmed the men never stepped inside. Video later confirmed this.

But something caught Foria’s eye on the safe room floor — droplets spattered on the dusty surface of collapsed ceiling panels.

“What’s this here? This is sweat,” he recalled thinking. “It must have rolled off their faces while they looked into the safe room,” he said.

A sample was sent for DNA analysis and ultimately returned a genetic profile police could use to match against potential suspects.

Harry Winston flew in a security agent to Chicago to assist the investigation.

Dumb luck, they determined, foiled the heist. A blow from a sledge hammer shook a painting or window blind in a room above the area where the men were laboring, triggering an alarm.

Foria quickly began to suspect an inside job.

A telltale had been discovered during construction three weeks before the opening.

Someone had placed a resistor on a wire leading to a sensor on a second floor stairwell that “would allow the security system to appear to be functioning when computer checks were performed; however, if someone or something had breached that specific area, the sensor would not show the interruption,” according to the police report.

The problem was fixed, and “this information was made privy to only a select few individuals,” the report states.

“There were other things, too,” Foria said. “They knew everything. Everything about the interior. They knew exactly where to go.”

“It reminded me of robbers in the movie ‘Ocean’s Eleven’ stepping over lasers . . . it was like the whole thing was from a movie or a book,” he said.

“They never looked directly at the security cameras. The best shot we had was the profile of one of the guys, and he was wearing a hoodie.”

Foria’s boss gave him to two weeks to focus solely on the case, a rarity.

The investigation uncovered a series of intriguing clues.

One discovery: a separate set of alarm sensors had been turned upside down, so they would detect movement on the ceiling, not the floor.

Between 50 and 100 workers had access to the store during construction. Scrutiny was given to electricians and alarm technicians.

Another clue: the video showed one of the burglars with a unique hand saw that Foria learned Eastern European laborers commonly brought with them to the United States.

The Interview

Foria’s main suspect was the worker who installed the sensors found upside down.

The man agreed to meet Foria at the police station at Belmont and Western.

“He didn’t seem perplexed at all. He said he was with his girlfriend the night of the break-in and claimed anyone could have turned those sensors upside down after he installed them,” recalled Foria.

“I’d looked into this guy. He had financial problems that seemed to fit,” Foria said.

Foria handed the man the profile picture of one of the burglars.

“He laughed when I showed him the photo. He said, ‘This looks like me,'” Foria recalled.

The man agreed to a submit a DNA sample, but it wasn’t a match.

And the DNA profile drawn from the sweat droplets didn’t turn up any hits when compared at the time to a database of convicted felons.

The ‘Monumental Hit’ That Wasn’t

No charges were ever filed in the case.

The Harry Winston corporate offices declined to comment.

Foria still thinks about the case from time to time.

“If they had got off with it, it would have been a monumental hit,” he said.

It’s possible the DNA, if run though the system again, could yield a match — if one of the burglars has been convicted of a felony since the crime happened.

But it’s unclear if the DNA has ever been run again. And even if such a match were discovered, the statute of limitations — a three-year window — has expired.

“That one still haunts me,” Foria said.

Blase Foria

Blase Foria, a retired Chicago detective, talks about the attempted diamond heist at Harry Winston that he worked on.| Tim Boyle/For the Sun-Times