SEFFNER, Florida (Reuters) - A wrecking crew on Sunday partly razed a Florida house where a sinkhole had swallowed up a man as he slept but the demolition team went about its job as carefully as possible to preserve the home's contents for survivors.

Rescue workers had given up the search for Jeff Bush, a 37-year-old landscaper, on Saturday. He was officially declared "presumed dead" by county officials after disappearing into the hole, which opened up under his bedroom on Thursday night.

Sinkholes are common in Florida due to the state's geology and they are virtually impossible to predict.

With a crowd of a few dozen family members and others watching, a boom crane clawed at the one-story home in suburban Tampa for about two hours, demolishing about half of it. The job was due to be completed on Monday.

Jeremy Bush, Jeff's brother, who had jumped into the sinkhole in a futile attempt to save him, said the family was discussing plans for a memorial service and a possible marker at the site.

Asked how he was feeling, Bush, 36, told Reuters: "Just sad, sad that they couldn't get my brother out."

"He was a good guy. He would give you the shirt off his back," Bush said of his brother.

Five other people in the house, which is owned by the family of Jeremy Bush's fiancée, had been preparing for bed Thursday when they heard a loud crash and Jeff Bush screaming.

STABILIZING THE PIT

Once the house is torn down, efforts will begin to stabilize the sinkhole, said William Puz, a spokesman for Hillsborough County. The hole was about 30 feet (9 meters) wide and 60 feet (18 meters) deep and filled with clay and debris. It is unlikely that Bush's body will ever be retrieved, officials said.

The crane's bucket first removed the garage eaves from the house and a U.S. flag there, carrying it to the sidewalk. Hillsborough County Fire Rescue workers folded the flag and handed it to family members.

The crane then probed through the master bedroom and swept family memorabilia, boxes, luggage, dresser drawers, framed photos, a woman's purse and other items out of the house and placed them near the sidewalk.

Crane operator Dan Darnell had an "emotional meeting" with family members after the work was halted, Puz said.

Before the demolition started, Jeremy Bush, a landscaper like his brother, was escorted by a deputy sheriff to the entrance of the driveway where he knelt and put flowers on the ground, bowing his head for a few minutes.

Wanda Carter, 49, who grew up in the house, said she could not watch as it was being torn down.

"We have each other and that's all that matters," Carter told reporters as she clutched a large family Bible, its cover torn off and bearing marks from the crane's bucket.

Sinkholes in Florida are caused by the state's porous geological bedrock, according to the Florida Department of Environmental Protection.

As acidic rainwater filters into the ground, it dissolves the rock, causing erosion that can lead to underground caverns, which cause sinkholes when they collapse.

Two nearby houses have been evacuated because the sinkhole has weakened the ground underneath them, and their residents probably will never be allowed inside again, said Jessica Damico of Hillsborough County Fire Rescue.

They were allowed 20 to 30 minutes in their homes on Saturday to gather belongings.