Investigators were able to determine that the debris that washed ashore on the French island of La Reunion was from a Boeing 777 solely based on photographs, CBS News has learned.

Investigators said they had a "high degree of certainty" Thursday that aircraft wreckage found on an island in the western Indian Ocean is a wing component unique to a Boeing 777 airplane, the same model as Malaysia Airlines Flight 370, which mysteriously vanished more than a year ago with 239 people on board.

Plane debris that washed ashore a French island is believed to be a part of a wing called a flaperon, a device which extends from the main wing of an aircraft to slow it down as it's beginning to land. Sources say it was the design of the part that confirmed for members of Boeing's Air Safety Investigation Team that it belonged to a 777.

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Boeing 777 maintenance manual shows the flaperon number 657BB which is a match with the photos of the debris. The flaperon number 657BB was further confirmation for investigators.

Graphic shows where the flaperon is located on a plane. CBS News

All the signs are pointing to a positive identification. Captain "Sully" Sullenberger, CBS News' aviation and safety expert, noted on "CBS This Morning" on Thursday said there is one missing Boeing 777 plane in the world right now -- MH370.

"It needs to be confirmed by the investigators, but it's a possible good first step in solving what has been one of the biggest aviation mysteries in history," he said.

Police and gendarmes carry a piece of debris from an unidentified aircraft found in the coastal area of Saint-Andre de la Reunion, in the east of the French Indian Ocean island of La Reunion, on July 29, 2015. Yannick PotouI/AFP/Getty Images

CBS News correspondent Seth Doane reports that authorities are calling this find a "significant development," but they caution it's still too early to know if the debris is a piece of MH370.

Doane reports that the flaperon will be taken to France for more analysis, including examining the barnacles to see if it matches something submerged for roughly 500 days.

The debris was discovered approximately 2,600 miles west of where searchers had been scouring the sea floor of the southern Indian Ocean in a 46,000 square mile search area off the coast of Australia.

Australian authorities, who have led the search, say models suggest the wreckage could have floated that far, carried by ocean currents, and that this find would likely not change the current search area.

"When you find a part like this, historically what we have found is that you will find other parts in the area," CBS News transport safety expert Mark Rosenker said.

There were also reports Thursday of a damaged suitcase found washed ashore on La Reunion. A local news website published photos of a man holding what was purportedly a tattered bag recovered from a beach near the wreckage.

Rosenker, a former chairman of the NTSB, told CBS News that investigators would now be pouring over the recovered part, looking for clues.

Map shows ocean currents for the region where debris has been found and where MH370 went missing. CBS News

"Was this metal torn? Was it crumpled? Had it been ripped in some shape or form? Is it pop marked? Does it have any type of char on it which would indicate a fire? All of that is going to be very important," Rosenker said.

293 passengers and crew were aboard the flight from Kuala Lumpur to Beijing, and victims' families have endured false leads before.

We've been through this many times," said K.S. Narendran, whose wife was one of the passengers. "I think it has really not helped us to either keep expectations high or to, in a sense, hope for some quick answers."

Doane reports that a group of Chinese victims' families have posted a letter online saying they are awaiting official confirmation of whether the piece of debris is indeed a part of missing flight MH370.

They say what matters the most to them, however, is where their family members are.

"We have had many false alarms before," Prime Minister Razak said. "But for the sake of the families who have lost loved ones and suffered such heartbreaking uncertainty, I pray that we will find out the truth so that they may have closure and peace."