NIGERIA’S aviation authority on Sunday announced the start of an investigation into the crash of a passenger airplane which killed nearly 200 people. Speaking to reporters here, Harold Demuren, director general of the Nigeria Civil Aviation Authority (NCAA), said that the investigation into the air crash has begun. "We don’t believe there are survivors,” he said, adding that the flight originated from Nigeria’s capital city Abuja. In a statement issued after the crash, Nigerian President Goodluck Jonathan declared a three-day mourning for the victims and promised a "fullest possible” investigation into the crash. Jonathan canceled all his public engagements scheduled for Monday and directed that the Nigerian flag be flown at half-mast for the three days of national mourning, according to the statement. The Dana aircraft crashed in a residential area in the Lagos metropolis, killing all those on board and 40 others living inside a two-story building hit by the aircraft. At the airport, hundreds of wailing relatives of passengers on the crashed air plane, besieged the local wing of the Murtala Muhammed International Airport (MMIA) in Ikeja,  seeking information on the flight. Tony Usidamen, spokesperson for the airline, who addressed the relations of the passengers outside the Departure Hall, read out the names of passengers who were on the ill-fated flight. Usidamen told the relatives of the passengers that he had no more details to give them,  saying that rescue operations were still ongoing at the crash site in Iju, Agege, near Lagos. The airline spokesperson later confirmed to reporters that there were no survivors in the crash. The aircraft, with registration number 5N-RAM, was said to have crashed around 4:00 p.m, local time. Efforts to rescue victims of the crash were hampered by the presence of a huge crowd of onlookers, miscreants and sympathizers. The inaccessibility of the crash area has also made it difficult for rescue teams, which include the police, Red Cross, Army, Federal Road Safety Commission, Nigeria Air Force and Fire Service, to get to the plane. Femi Osanyintolu, General Manager of the Lagos State Emergency Management Agency, told reporters that the building on which the plane landed must be collapsed for any rescue operation to take place. He also said they had to be cautious in collapsing the building because it was situated in a residential area. The following are major aircraft catastrophes that took place in Nigeria since 2000: