Malaysia Airlines Flight MH370 took off from Kuala Lumpur and heading toward Beijing on the morning of March 8, but lost contact with air traffic control an hour later and disappeared off the radar.
No trace of the plane and the 239 people on board have been found and few details about what could have happened to the plane have been released.
Here's what we know now as of now about the investigation into missing flight MH370.
Check out ABC News' photos of the search for the flight here, too.
Malaysia Unsure About Which Direction Plane Was Going
- Flight MH370 departed Kuala Lumpur International Airport in Malaysia, headed for Beijing, China, around 12:41 a.m. local time on Saturday. It showed up on radar two minutes later.
- Malaysia's radar tracked flight MH370 until 1:20 a.m. when the flight dropped off the radar. At the time the plane was on its route over the South China Sea heading for the southern tip of Vietnam. An air traffic controller told the plane's captain he was about to be handed over to air traffic control out of Ho Chi Minh City. The pilot responded, “All right, good night.” Authorities initially said this was the last time they had contact with the flight.
- Authorities have discovered that a flight showed up on the country's military defense radar at 2:15 a.m. local time in the Straits of Malacca, hundreds of miles due west of their last contact point and far from its route to Beijing. They said today that contact could possibly have been MH370.
- The military radar also showed something make a turn back, meaning some aircraft reversing course, but they are not sure whether it was flight MH370. Because of the uncertain radar data, they are not sure of the plane's last position.
- The engines on the plane, manufactured by Rolls Royce, are designed to send pulses of data at certain stages of the flight. Malaysian authorities said today they are working with Rolls Royce to determine what data MH370's engines sent before it went missing.
Search Focuses on Possible Debris Sighting and Wide Area of Open Sea
- An oil rig worker stationed off the coast of Vietnam reported seeing a burning object fall into the ocean early Saturday, which could help show a fiery crash doomed the plane. The worker, a New Zealand resident, wrote an email to Vietnamese authorities explaining what he saw.
- Vietnamese authorities said today they searched the area and did not see any evidence of a crash or debris.
- Authorities in Malaysia said today they will "not reduce the tempo" and "not spare any effort" in searching for signs of the plane after five days without any hard evidence of what could have happened to Flight 370.
- The search has been broadened to encompass 27,000 square nautical miles, an area roughly the size of Indiana.
- Forty-two ships and 39 aircraft from 12 countries are scanning the area in the Straits of Malacca and South China Sea where the plane is last thought to have traveled.
- Despite reports, there have been no plane parts or signs of passengers found.
- Aviation experts say there are two possible causes of the disappearance: mechanical error or human error on board, which could include an electrical outage, a fire, a hijacking or bomb, and many other reasons. There is no hard evidence one way or another at his point, they say.
- The transponders on board the plane that transmit signal's about the plane's location were somehow disabled or turned off, according to authorities. Investigators are looking at how and why they transponders were not functioning.
- Authorities have not ruled out terrorism but have found no evidence of it.
- Malaysian government officials today played a recording of the pilot's last recorded words for passengers' family members. The air traffic control worker said to the pilot, "We have to hand you over to Ho Chi Minh City," to which the pilot replied, "All right, goodnight."
- Four passengers who were waiting on the stand-by list to board flight MH370 were given seats on the plane after four ticketed passengers did not show up for the flight.
- 239 people were on board the flight, made up of 227 passengers (including one infant and one toddler) and 12 crew members.
- Three Americans, including two children, are among the missing. Philip Wood, 50, an IBM executive, had just come from Texas where he was visiting family on his way to Beijing.
- Fourteen nationalities were on board, though 152 passengers were Chinese.
- Twenty passengers on the plane worked for the Austin, Texas, company Freescale Semiconductor. Another passenger, Chng Mei Ling, worked as an engineer for the Pennsylvania company Flexsys America LP.
- Pilot Zahari Ahmad Shah, 53, was a veteran pilot who joined Malaysia Airlines in 1981 and had over 18,000 flying hours.
Fake Passports Used By Two Passengers
- Investigators discovered that two passengers used stolen passports, one from Austria and one from Italy, to board the flight.
- Interpol identified the two as Iranians Seyed Mohammad Reza Delavar, 29, and Pouria Nourmohammadi, 18, and said they have no known links to militant groups, downplaying the possibility they were terrorists.