ATLANTA, Georgia (CNN) -- When Atlanta police officers Bryan Ernest and Bernatt Collins get a burglary call, they know that the house they walk into will probably be stripped, right down to the materials inside the walls.
Calls to Atlanta, Georgia, police are increasing for vacant homes ransacked by burglars.
They are part of a special burglary detail formed to watch the increasing number of vacant houses resulting from unpaid mortgages.
Drawing their guns, the officers approach an empty house and shout "Atlanta police!" before entering. It's a burglary call, and they have to expect the worst.
But the officers usually get to a home long after the thief has gone, leaving Sheetrock hanging from the walls like shredded cardboard, giant holes in the ceilings and exposed wiring minus its valuable copper parts. Watch foreclosed homes gutted by thieves »
"This is all copper that they are taking out down the walls," Ernest said. "You can see where the outlets were, any bit of copper they take."
The Atlanta Police Department doesn't know how many homes have been hit. The police are not keeping records that differentiate between thieves who steal from occupied homes and those who rip out copper and appliances from vacant houses, many of them the result of the nation's foreclosure crisis. See foreclosures across the country »
Across the country, law enforcement officials report that more empty houses are being burglarized. Developers are unable to sell newly built homes, and landlords have trouble renting properties. Atlanta is one of the few police departments that has formed a special vacant home burglary team.
Rising copper prices are driving some of the thievery, but that's not all the burglars are taking.
Wanda Vaughn and her mother, Vera, operate a contracting service. Banks and homeowners hire them to fix what's been broken and/or replace stolen items after a thief strikes. Sometimes they replace everything in a home and board it up to prevent more burglaries.
Wanda Vaughn has seen water heaters ripped out and dumped on hardwood floors and carpet. "This has to be torn out and replaced," she said while walking through a burglarized house in Atlanta. "The baseboards have to be torn out because of mold on all the carpet padding and subflooring."
Estimated damage: between $15,000 and $20,000 for only about $40 worth of copper.
"They took the stove, the refrigerator, the cabinets, everything, including the kitchen sink!" Vaughn said.
Although some areas Ernest and Collins have patrolled over the past year are areas typically targeted by criminals, the burglaries are becoming more prevalent in affluent neighborhoods.
"The neighbors have been calling and saying they are hearing banging or seeing a vehicle that's parked at a house that's supposed to be vacant," Ernest said.
Some thieves carry book bags full of copper. Others push baby carriages and shopping carts full of stripped building materials. "Whatever they can push or pull to get this stuff out, they use," Collins said.
County and city code enforcement departments often have difficulty locating homeowners. Some live out of town, and others have abandoned the houses after being unable to make mortgage payments, police said.
House investor Bob Forbes said it's a constant battle when a home he owns is burglarized. Forbes usually installs steel cages around the air conditioning units outside the houses, but thieves take the air conditioner apart and pull the smaller pieces through the cage, leaving an empty concrete slab and padlock dangling off the bars of the cage.
"In one house, I betcha I replaced the air conditioning condensers three times, and they kept coming back," he said.
"If you don't have somebody in the house, it's going to happen. In one house that was about to close escrow, the plumbing was perfect. I came in the next day, and the plumbing, including the toilets, was gone!"