Several Faithway Drive houses were determined by investigatorsto be in danger, as the authorities warned the sinkhole wasunstable and could grow.”We are still delineating the edge of the sinkhole. We don’tknow if it has changed,” newspaper The Tampa Tribune quoted thePresident of an engineering company, Larry Madrid, who also addedthat heavy equipment ‘should arrive on the scene later today orSunday’.“I cannot tell you why it has not collapsed yet,” AP hasquoted, Bill Bracken, the owner of another engineering companycalled to assess the sinkhole. He described the earth below as a“very large, very fluid mass.”Florida is highly prone to sinkholes because of the undergroundprevalence of limestone, a porous rock that easily dissolves inwater, creating caverns.“You can almost envision a piece of Swiss cheese. Any housein Florida could be in that same situation,” sinkhole expertTaylor Yarkosky told AP.On Saturday rescuers ended their effort to find Bush, who hadvanished under the earth, sucked in into a sinkhole that suddenlyopened under his bedroom in a suburban Tampa home.After lowering listening devices and cameras into the holerescuers did not detect any signs of his body. Officials said forsafety reasons they are now planning to demolish the whole houseinto the hole.The hole, estimated to be 20 feet across and 20 feet deep,literally swallowed the 37-year-old man, along with his bed,television and dresser into the ground as it broke through theconcrete floor of his bedroom on Thursday.As Bush was presumed dead on Friday, his brother described as hejumped in to try to save his sibling that he “heard himhollering my name to help him,” said Jeremy Bush.Six people, including a 2-year-old child, were inside the houseat the time of the incident.“I feel in my heart he didn’t make it,” Bush told TampaTV station WFTS. “There were six of us in the house, five gotout.”When the emergency team got to the scene “all they could seewas a part of a mattress sticking out of the hole,” saidHillsborough County Fire Rescue Chief Ron Rogers.County administrator Mike Merrill described the home as“seriously unstable,” warning that more lives could be lostif people continue to occupy the house.A 400-foot sinkhole near Orlando in 1981 swallowed up fivesports cars, two businesses and a three-bedroom house. More than500 sinkholes have been reported in Hillsborough County since1954.