One week after EgyptAir crash, the mystery deepens

 A week after EgyptAir Flight 804 vanished from radar and crashed into the Mediterranean Sea, the cause still remains a mystery. Here's the latest information about the disaster that killed all 66 people on board and why determining what happened is proving difficult: 

Have the black boxes been found?

 No. The chief of EgyptAir says Egypt has contracted two foreign companies, one French and one Italian, to help locate the plane's flight data recorders. Safwat Masalam said Wednesday the companies will be working with Egyptian search teams to find the black boxes, which could give clues as to what happened in the final moments of the flight. The companies have not been identified, the Associated Press reported.

The recorders, which are actually colored orange, emit "pings" that can be detected with sonar and have batteries that last about 30 days. After that, the search would become much more difficult in water about 2 miles deep. 

Although regulators have agreed to increase the transmission time and range of the beacons to improve the chances for finding the boxes, the rules do not go into effect until 2018 — which is too late for the EgyptAir flight, Reuters reported. 

What has been recovered so far?

Egyptian military forces have found debris, including body parts, from the missing plane 180 miles from the Egyptian coastal city of Alexandria. Photographs released by the Egyptian army show little remains of the devastation — just mangled bits of debris, tattered clothing and a life vest, among other objects. Most of the passengers' remains and large sections of the plane have not been located, adding to the uncertainty about the cause of the crash.

Why have there been debates over debris?

Aviation safety experts told The Wall Street Journal  that Egypt could be mishandling debris gathered from the plane, which could compromise the investigation into the cause of the crash. Photographs show people handling items without protective clothing and putting the evidence on unprotected surfaces, the Journal reported. Egypt's military has not commented on the claims about the recovery process. Investigators need to analyze debris to determine whether chemical residue from explosives, fire or smoke is present, according to the Journal. 

Was it a terror attack?

Nobody has claimed responsibility for the incident yet. In contrast, the Islamic State quickly took credit for destroying Russian Metrojet Flight 9268, which blew up over Egypt’s Sinai in October, after taking off from the resort town of Sharm el-Sheik.

Egyptian Civil Aviation Minister Sherif Fathi said immediately after the plane crashed that the airliner was more likely brought down in a terror attack rather than a technical malfunction. But he had no evidence to base that statement. The Egyptian investigation committee said the jet had not shown any sign of technical problems before takeoff, Reuters reported.

What do we know about the plane's final moments?

The Airbus A320 crashed early Thursday after flying at 38,000 feet, when it suddenly swerved left 90 degrees, then right a full 360 degrees before descending thousands of feet and vanishing from radar.

An automated system sent messages indicating smoke was detected in multiple spots on the plane minutes before it crashed, according to French investigators.

The sudden swerve and possible presence of smoke don't make clear whether a bomb or accidental fire might have brought down the plane.

What about the victims?

Egypt says no one survived the crash. The flight, from Paris to Cairo, carried 56 passengers and 10 crewmembers. Passengers included 15 French, 30 Egyptians, two Iraqis, one Briton, one Kuwaiti, one Saudi, one Sudanese, one Chadian, one Portuguese, one Belgian, one Algerian and one Canadian, according to EgyptAir. Two babies were on board, officials said.