Beirut - The first sign of trouble was a flash of light on the horizon on Monday - and then witnesses said the Boeing 737 tumbled like "fire falling down from the sky" into the stormy Mediterranean Sea.
All 90 aboard were feared dead in the pre-dawn crash. Lebanon's leaders ruled out terrorism while investigators collected witness accounts in hopes they could provide clues. Aviation experts cautioned it was too early to know what brought down the Ethiopian Airlines jet - particularly without the black boxes.
Many people were giving DNA samples to help identify the remains of their loved ones; one man identified his 3-year-old nephew by the boy's overalls.
"Please find my son," pleaded Zeinab Seklawi, whose 24-year-old son Yasser was on Flight 409, which was headed to the Ethiopian capital, Addis Ababa.
At the Government Hospital in Beirut, Red Cross workers brought in bodies covered with wool blankets as relatives gathered nearby. No survivors had been found by nightfall, and the health minister told reporters 21 bodies had been recovered. Marla Pietton, wife of the French ambassador to Lebanon, was among those on board, according to the French Embassy.
The Boeing 737-800 took off at about 02:30 local time in driving rain, lightning and thunder, and went down 3.2km off the coast, said Ghazi Aridi, the public works and transportation minister.
Hours after the crash, pieces of the plane and other debris were washing ashore, including a baby sandal, passenger seats, a fire extinguisher, suitcases and bottles of medicine.
Doubts over witness reports
"We saw fire falling down from the sky into the sea," said Khaled Naser, a gas station attendant who saw the plane plunge into waters that had reached 18 degrees Celsius by Monday afternoon.
The Lebanese army also said the plane was on fire shortly after take-off. A defence official said some witnesses reported the plane broke up into three pieces.
Aviation safety analyst Chris Yates said reports of fire could suggest "some cataclysmic failure of one of the engines" or that a bird or debris had been sucked into the engine.
He noted that modern aircraft are built to withstand all but the foulest weather conditions.
"One wouldn't have thought that a nasty squall in and of itself would be the prime cause of an accident like this," said Yates, an analyst based in Manchester, England.
Still, one prominent analyst cast doubt on the accuracy of witness reports of flames.
"Eyewitnesses almost always report aircraft exploding in the sky or seeing heavy, heavy flames," said William Voss, head of the Flight Safety Foundation, a nonprofit advocacy group based in the United States.
Beirut airport is equipped with a sophisticated weather radar that flight controllers use to guide planes around the towering thunderheads, accompanying winds and lightning that can cause structural damage to airframes.
The electrically charged clouds are part of massive storms that have regularly formed off the Lebanese coastline this winter.
Take-offs in such poor weather conditions are particularly difficult, and the controllers often assist pilots to find a way through the storm.
'Sabotage is ruled out as of now'
The Boeing 737 is considered one of the safest planes in airline service. The jet was first introduced in the 1960s, and today is the workhorse on many short- and medium-range routes.
Still, over the past 15 years it has been involved in a series of incidents and crashes linked to problems with a valve in the rudder assembly. The valve reportedly would malfunction and cause the rudder to turn independently of the pilot's commands.
The problem was considered resolved after operators of older Boeing 737s were ordered to carry out inspections and upgrades of the rudder control systems.
Sidney Dekker, a professor of flight safety at the School of Aviation at Lund University in Sweden, said the rudder problem has been corrected by the manufacturer and that he'd be "hugely surprised" if it had anything to do with the crash.
Dekker, himself a 737 pilot, said that if reports of an engine fire proved to be correct, the accident could have resulted from a loss of control at a relatively low altitude where it would have been difficult to recover.
He noted that the 737's engines had extra power in order to fulfill performance requirements in the event of the loss of an engine at take-off. This tended to produce a turning movement of the entire aircraft - known as yaw - toward the dead engine.
Poor visibility in low clouds combined with high winds may have contributed to the problem faced by the pilots trying to regain control, he said.
An international rescue effort, with help from the United States, Cyprus and the UN, was launched after the crash. The weather hampered the search as ships plowed through tall waves. Lebanese Prime Minister Saad Hariri announced a day of mourning and closed schools and government offices.
Lebanese President Michel Suleiman said terrorism was not suspected in the crash of Flight 409. "Sabotage is ruled out as of now," he said.
Ethiopian Airlines' CEO Girma Wake said the aircraft had been serviced on December 25 and passed inspection. He said the plane had been leased in September from New York-based CIT Aerospace. A CIT spokesperson declined to comment and referred questions to Ethiopian Airlines.
The state-owned Ethiopian Airlines has long had a reputation for high-quality service compared to other African airlines, with two notable crashes in more than 20 years.
A hijacked Ethiopian Airlines jet crash-landed off the Comoros Islands in the Indian Ocean when it ran out of fuel in November 1996, killing 126 of the 175 people aboard. In September 1988, an Ethiopian Airlines jet crashed shortly after taking off when it ran into a flock of birds, killing 31 of the 104 people on board.
Ethiopian Airlines announced last week that it had signed an agreement with Boeing to buy 10 more of the 737-800s at an estimated $767 million. The order will expand the airline's fleet from the 36 aircraft it has now - not including the 737-800 that crashed on Monday.
The plane was carrying 83 passengers and seven crew, Lebanese officials said. Aridi, the transportation minister, identified the passengers as 54 Lebanese, 22 Ethiopians, one Iraqi, one Syrian, one Canadian of Lebanese origin, one Russian of Lebanese origin, a French woman and two Britons of Lebanese origin.
Ethiopian Airlines reported that there were 82 passengers and eight crew; the discrepancy could not immediately be explained.
Weeping relatives streamed into Beirut's airport to wait for news on their loved ones. One woman dropped to her knees in tears; another cried out, "Where is my son?"
Andree Qusayfi said his 35-year-old brother, Ziad, was traveling to Ethiopia for his job at a computer company, but was planning to return to Lebanon for good soon.
"We begged him to postpone his flight because of the storm," Qusayfi said, his eyes red from crying. "But he insisted on going because he had work appointments."