Here's how three brazen bandits ransacked a Manhattan diamond store and walked away with nearly $900,000 worth of baubles in a heist reminiscent of the movie "Ocean's Eleven."

Police yesterday released a 24-second video of the thieves -- who wore masks, hats and dark clothing -- using their gloved hands to quickly empty display cases at Ultra Diamond on Sixth Avenue at 23rd Street, in the Flatiron
District, at 5 p.m. Christmas Day.

In a break-in style similar to one portrayed in the hit 2001 George Clooney movie about a Las Vegas casino robbery, the crafty crooks climbed to the roof of an adjacent building and crossed over to the roof of the store, which also houses a Burlington Coat Factory.

Two of them smashed a hole in the store's wall, possibly with a sledgehammer and crawled inside, according to law-enforcement sources.

To cover their tracks, they managed to disable some of the store's video cameras and its recording system.

But they didn't foil all of the surveillance equipment, because investigators found at least one camera still functioning, sources said.It provided the video that police released yesterday.

While inside, the bandits used a claw hammer to smash several glass display cases, and began piling up their loot.

As this was going on, one of the crooks used a cellphone to alert the third man, who snaked his way through the hole in the wall.

All three men, who seemed to be highly professional, then broke into an office in the store and looted more jewelry from a safe.

When they were done, the men left through the hole in the wall with their loot, which included gold and platinum wedding bands, diamond engagement rings, watches, earrings, bracelets and other jewelry.

The total haul was valued at $897,000, but cost $321,000 wholesale.

The thieves apparently left the way they came, via the adjacent building, while the streets below were largely deserted because of the holiday.

"We're extremely grateful that no one was in the store at the time," said Kris Land, a spokesman for Ultra. "It's a
heartbreaking situation."

The store also expressed gratitude to investigating police.

"We are extremely pleased with the amount of attention being put on this," Land said.

The suspects remain at large.

Police dismissed speculation that the heist was carried off by a disgruntled current or former worker for the diamond firm.NY POST