Investigators are trying to determine what caused a Spanish tourist jet to break up in flames as it took off from Madrid's airport, killing 153 people.
The American-built McDonnell Douglas 82 plane, operated by Spanair, exploded into flames shortly after take off. It was destined for the Canary Islands.
The unstable aircraft then veered off the runway before breaking up, with fire spreading rapidly through the fuselage.
Spanish Transport Minister Magdalena Alvarez says 153 people were killed and 19 injured.
There were 162 passengers aboard with 10 crew members, four of whom were travelling as passengers. Twenty-two children were among the passengers.
The airliner had earlier begun taxiing to the runway, before turning back because of an undisclosed technical problem, which delayed the takeoff by an hour.
The two black boxes have been found and are to be analysed.
Spanish media said the pilot had earlier signalled a malfunction in an exterior temperature gauge, which was fixed before takeoff.
Spain's Secretary of State for Communication Nieves Goicoechea ruled out terrorism, saying there was "no doubt that it was an accident".
It was the deadliest air accident in Spain since a Boeing 747 of the Colombian airline Avianca crashed in Madrid in 1983, killing 180 people.
The most deadly accident in the history of civil aviation occurred when two Boeing 747s collided at Tenerife airport in Spain's Canary Islands in 1977, killing 583 people.
The Spanish government has declared three days of national mourning following the crash.