Investigators have still not found the bulk of the wreckage from Malaysia Airlines Flight 370 or determined why the plane went down, and time is running out. The search for the missing plane in a 46,000-square mile zone in the Indian Ocean is expected to end in December.

Families of passangers who were on the plane when it went missing have accused investigators of ignoring debris linked to the aircraft or delaying the investigation. "Credible evidence is turning up, why are they not investigating it?" Grace Subathirai Nathan told BBC News in July. "From day one we've had the notion they want an end to it, to sweep it under the rug. How can potential evidence be unattended for a month? It's becoming a farce."

The plane vanished in March 2014 en route from Kuala Lumpur to Beijing. There were 239 people on board. Here's what investigators have found so far: 

Australian and Malaysian authorities confirmed Friday that debris found on the Indian Ocean island of Mauritius was a piece of the wing flap from the Boeing 777 aircraft. "The piece has been identified as a trailing edge splice strap, incorporated into the rear spar assembly of a Boeing 777 left outboard flap," Malaysian Transport Minister Liow Tiong Lai said.

In July, investigators sent a piece of an airplane wing suspected to be from the missing flight to Australia for analysis. Authorities in Canberra said at the time the debris found in June on Pemba Island, near Tanzania, appeared to be a "large piece of what is likely to be a wing flap."

In March, a lawyer from Seattle found debris in Mozambique that Malaysian officials at the time said had a "high possibility" of being from MH370.

In December, a teenager from South Africa found a wing part that Australian officials said was "almost certainly" from the missing flight.

Officials also linked a flaperon that turned up on Reunion Island last year to MH370. An engine part and an interior piece are also being investigated. All of the debris washed up near South Africa, Mozambique and Madagascar.