CLARENCE CENTER , New York ( CNN ) -- Recovering all the bodies from Thursday 's deadly passenger plane crash may take four days as investigators work through freezing temperatures and piles of wreckage , a federal transportation official said Saturday . Only a few pieces of the Continental Connection Dash 8 turboprop were recognizable after the crash . `` The medical examiner believes that three to four days are going to be required to recover the victims of this crash , and they 're in the process of doing that , '' Steve Chealander of the National Transportation Safety Board said . `` They 've already pulled some of the folks out of there , but they 've got a long way to go . '' All 49 passengers aboard Continental Connection Flight 3407 died when the 74-seat Bombardier Dash 8 Q400 turboprop crashed into a home in Clarence Center , New York , on Thursday night . A 61-year-old man in the house died also , but his wife and daughter survived . Fifteen bodies have been recovered , and efforts to identify the victims and conduct autopsies are under way , Erie County Health Commission Anthony Billittier said Saturday evening . A federal disaster mortuary team was called to assist local forensic officials . Despite reports from local authorities who said the plane hurtled toward the house from a sharp nosedive , Chealander said the current orientation of the plane indicates that it fell flat on its belly . The Continental flight from Newark , New Jersey , operated by Colgan Air , crashed about 10:17 p.m. Thursday northeast of Buffalo Niagara International Airport . Follow the plane 's path » . Chealander said the recovery effort and the investigation have been hampered by freezing temperatures as authorities try to sift through the wreckage of the flight and the home it struck . Some parts of the plane have fallen as deep as the basement , he said . `` Keep in mind , there 's an airplane that fell on top of a house , '' he told reporters . `` The house and the airplane are together . '' Authorities said it would probably take weeks to identify remains of the victims , with DNA testing required in many cases because of the intensity of the crash and subsequent fire . A 2-square-mile area around the crash site , about 6 miles from the Buffalo airport where the plane was headed , remained sealed off Saturday as investigators sought to determine the cause of the crash . But the extent of the restricted area belied the concentrated force of the impact into the one house . Watch what investigators are saying » . Karen Wielinski was watching television inside the house when she heard a plane making an unusually loud noise . `` I thought to myself , 'If that 's a plane , it 's going to hit something , ' `` she told Buffalo radio station WBEN . `` And next thing I knew , the ceiling was on me , '' she said . Wielinski and her daughter Jill , 22 , were in the front of the home , and they escaped the house with minor injuries . Wielinski 's husband , Doug , who was in the dining room , was killed . On Friday , federal investigators released information from the plane 's cockpit voice and flight data recorders , indicating that icing may have been a major factor in the crash . The plane 's pilot and co-pilot discussed `` significant ice buildup '' on the plane 's windshield and wings as it descended toward the Buffalo airport . The plane underwent `` severe '' pitching and rolling motions after the landing gear was lowered and wing flaps were set for the approach , Chealander said . There was a mix of sleet and snow in the area , but other planes landed safely at the airport about the time the flight went down . Chealander said the flight crew reported that visibility was about 3 miles and there was snow and mist as they descended . The voice and data recorders indicated that the plane 's internal de-icing was on during the landing approach , he said . `` A significant ice buildup is an aerodynamic impediment , '' he added . Find out why » . Keith Burtis was driving about a mile from the crash site when he heard the impact . `` It was a high-pitched sound , '' Burtis said . `` It felt like a mini-earthquake . '' A ball of fire filled the night sky as the jet fuel erupted , Burtis said , and he saw a steady stream of fire trucks rush past as smoke billowed . At least nine volunteer fire departments responded . Watch iReporters ' close-up accounts » . Among the passengers killed was Beverly Eckert , widow of a September 11 attack victim . Also aboard was Alison Des Forges , senior Africa adviser for Human Rights Watch , one of her colleagues said . Des Forges spent four years in Rwanda documenting the 1994 genocide and had testified about the atrocity and the situation in central Africa to Congress and the United Nations , according to the organization . Read more about the victims . Also on the flight was Susan Wehle , a cantor at Temple Beth Am in Williamsville , outside Buffalo , a synagogue official said . Colgan Air identified the crew as Capt . Marvin Renslow , the pilot ; First Officer Rebecca Shaw , who was co-pilot ; and flight attendants Matilda Quintero and Donna Prisco . In addition , an off-duty crew member , Capt . Joseph Zuffoletto , was onboard . `` This is easily the saddest day in the history of our airline , '' said Philip Trenary , the company 's CEO .
NEW : 15 bodies recovered ; identification could take weeks . The search for the missing passengers and crew of Malaysia Airlines Flight 370 has been called off after a new analysis showed that debris from the plane was likely to have washed up on Reunion Island in the Cold weather , extent of wreckage could prolong recovery as much as four days . NEW : Orientation of plane indicates that it fell flat on its belly , NTSB says . De-icing equipment was turned on at time of crash , investigator says .