Fears of on-ground deaths in Nigeria plane crash (CBS/AP) LAGOS, Nigeria - Emergency workers in Nigeria used cadaver dogs and cranes to search for corpses Monday at the site where an American-built airliner plunged to Earth, killing all 153 aboard. The Dana Air jetliner smashed into businesses and crowded apartment buildings near Lagos' Murtala Muhammed International Airport, the worst air disaster in Nigeria in nearly two decades. Rescue officials said they fear many more people may have perished on the ground. "The fear is that since it happened in a residential area, there may have been many people killed," said Yushau Shuaib, a spokesman for Nigeria's National Emergency Management Agency. The twin-engine jet appeared to belly-flop into an apartment building in a densely-populated suburb of Lagos close to Murtala Muhammed International Airport, reports Tony Guida. The plane tore through roofs, sheared a mango tree and rammed into a woodworking studio, a printing press and at least two apartment buildings before stopping. The plane was heading to Lagos from Abuja, the capital, when it went down. A white, noxious cloud rose from the crash site that burned onlookers' eye. Pieces of the plane were scattered around the muddy ground. A Nigeria Red Cross report said that 48 bodies had been recovered, with more being dug out from the rubble. Dozens of residents pitched in to drag a fire hose to the crash site. The dead included at least four Chinese citizens, the official Chinese news agency Xinhua reported late Sunday, citing Chinese diplomats in Nigeria. Officials at the Chinese embassy in Nigeria could not be reached for comment by the AP. Two of the crash victims were Lebanese, according to state-run Lebanon's National News Agency. The NNA identified them as Nadim Chediac, an architect who has a Lebanese father and Nigerian mother, and Roger Awwad, an investor. In the wake of the crash, Nigeria's president has declared 3 days of national mourning. Witness describes Nigeria plane crash horror Plane crashes in Nigeria, all 153 aboard dead On Monday morning the debris still smoldered. Some people wore masks to try and protect themselves from the stench of the dead, as police with cadaver dogs searched for bodies inside the wreckage. Overnight officials had brought in a large crane from a local construction company to lift pieces of debris away, and blow torches to cut through what remains of the plane. Using the crane rescue workers lifted the tail of the aircraft; the metal shrieked as it was raised skyward and then dropped down. Rescue workers search for bodies at the site of a plane crash in Lagos, Nigeria, Monday, June 4, 2012. (Credit: (AP Photo/Sunday Alamba) The cause of the crash remained unclear. The pilots radioed to the Lagos control tower just before the crash, reporting engine trouble, a military official said. The official spoke on condition of anonymity as he was not authorized to speak to journalists. Rescue workers searched for the aircraft's black box recorders where flight data is stored, said Harold Demuren, the director-general of the Nigerian Civil Aviation Authority. Demuren said the Nigerian registration number of the Boeing MD-83 was 5NRAM. Aviation databases show the plane was exported to Nigeria in early 2009. It was first delivered in 1990 with the U.S. registration number N944AS to Alaska Airlines and it suffered two minor incidents while in the Seattle-based airline's service, according to databases of the Federal Aviation Administration and the Aviation Safety Network. On Nov. 2, 2002, the plane made an emergency diversion due to smoke and electrical smell in the cabin, and on Aug. 20, 2006, the plane was evacuated after landing at Long Beach, Calif., because of smoke in the passenger cabin. Boeing said in a statement on its website that the company is ready to provide technical assistance to the Civil Aviation Authority on Nigeria through the U.S. National Transportation Safety Board.