Residents of a wealthy California neighborhood have been left terrified after robbers ransacked their condos as it was being fumigated.
The break-ins happened inside the Del Ray Plaza complex in Playa del Rey, as it was tented up and fumigated from December 11-13.
Residents of the building, located on the westside of Los Angeles, were promised around-the-clock security by the homeowners association.
Despite this, thieves ransacked 23 units of a total 39, making off with cash, jewelry, and other valuables while leaving the vacant homes in disarray.
'We have 23 doors that have been smashed. We've got places that have been looted like you have no idea,' said Loren Brown, a resident, who spoke with KTLA News.
Brown added: 'Cash is gone, guns are gone. The people who were in here knew what they were doing.
'They were wearing respirators. This does not feel like it's an organic thing. This is somehow, to me, an inside job.'
Several people reported seeing lights on inside the building during the fumigation , despite residents being told to turn them off before they vacated the premises.
One of the intruders, who was seen wearing a gas mask, was eerily captured on home security footage opening the front door of the unit before letting himself in
The burglars were able to destroy 23 out of the 39 total units in the building - stealing cash, jewelry and other valuables
Residents of the building, located on the westside of Los Angeles , were promised around-the-clock security by the homeowners association
'That was the first clue,' Brown added. 'But we figured we had 24-hour security guards, things were being watched and it's all okay.'
One of the intruders, who was seen wearing a gas mask, was eerily captured on home security footage opening the front door of the unit before letting himself in.
He was seen slowly walking around the dark apartment while equipped with a flashlight - seemingly searching for things he deemed worthy of taking.
Carol Fontaine, the building's HOA president, was one of the victims targeted in the mass robbery.
When she returned to her unit on Friday, she was met with the sight of a smashed front door, a trashed bedroom and a destroyed closet - her personal belongings found spewed all across the floors rather than the spaces she left them in.
She said: 'It's quite devastating for a lot of us. A 24-hour security was ordered and patrolling outside and then I got a call from the termite company saying we've had break-ins. All floors were hit.'
The thieves escaped with several of her valuables, including jewelry and ammunition.
Residents were left questioning how the burglars could have spent that much time stealing and vandalizing their luxury building without anyone noticing.
As of this month, the average rent in Playa Del Rey is $2,461 - 58 percent higher than the national average - making it one of the most expensive cities in the United States, Apartments.com reported.
Carol Fontaine, seen here, the building's HOA president, was one of the victims targeted in the mass robbery
The burglars, who were captured on one unit's home security footage, appeared to be wearing gas masks - leading fearful residents to believe that they are either professionals or that the crime was an inside job
The aftermath of the mass robberies consisted of dozens of destroyed front doors around the building
Residents are now also working closely with law enforcement as investigators attempt to gather evidence in the robberies.
The terrifying break-ins come just five months after another nearby condominium complex was plagued with suspicious fires.
Marina City Club, which is located in the nearby wealthy community of Marina del Rey, is just a ten minute drive away from where the robberies took place.
The building experienced a series of suspected arson attacks this summer - leading to fire engines and bright flashing lights becoming a normal sight for its residents.
'We have a fire like once a week, and this has been going on since May,' Teri Hirano, a longtime resident of the building, told NBC Los Angeles in July.
The fires were said to have been started with the use of toilet paper and other combustible materials.