The head of Spain's civil aviation said the Spanair plane that crashed in Madrid Wednesday must have suffered more than one kind of failure. Meanwhile, grieving relatives are continuing efforts to help identify the remains of the 153 people who were killed. Sabina Castelfranco reports from Rome.

Just 19 people survived Wednesday's crash of the Spanair twin-engine plane bound for the Canary Islands from Madrid. It was Spain's worst air disaster in 25 years.

As the investigation to determine the cause of the disaster continued, the head of Spain's civil aviation, Manuel Batista, said there was more than one breakdown. He said engine failure alone would not have been enough to bring the plane down. He added that modern aircraft are designed to fly on just one engine in an emergency.

It may take months to establish what caused the plane crash. But useful details are expected to come from the two recovered black box (flight data) recorders. The Spanish government says it has much information to work with, including video footage of the plane's takeoff from airport cameras.

Spain's deputy Prime Minister Maria Teresa Fernandez de la Vega said the investigation commission is working very intensively and hand in hand with foreign experts. She added that the results would be given to a judge, but details would be made public as soon as possible.

Meanwhile grieving relatives of those killed in the crash continued with the ordeal of identifying bodies. Many bodies were burned beyond recognition and forensic teams are taking DNA samples from relatives.

Spain is observing three days of mourning and an official funeral presided over by Madrid Archbishop Antonio Maria Rouco has been scheduled for Sept. 1.