Seven weeks after Malaysian Airlines Flight 370 disappeared from the skies, the search for the missing plane has led to conspiracy theories of terrorism and suicide, to mysterious floating debris and underwater drones searching the depths of the Indian Ocean.
As of Friday the U.S. Navy underwater drone Bluefin 21 has searched 95 percent of the 120-square-mile search area believed to be the crash site in the southern Indian Ocean, NBC News reported.
Despite the relentless multinational search, investigators have not found any signs of the plane or its 239 passengers. Officials now fear the search could go on for years, the station reported.
"We went all-in on this small area and didn't find anything," a U.S. defense senior official told Reuters on condition of anonymity, according to NBC News. "Now you've got to go back to the big area. And now you're talking years."
Investigators believe MH370 continued flying for hours after it was last known to by flying between Malaysia and south Vietnam. The plane's communication systems are also believed to have been deliberately shut off not long after it took off from Kuala Lumpur on March 8 headed for Beijing.
The Indian Ocean has been the focal point of the search ever since "pings" believed to be from the plane's black box were picked up in the water at the beginning of April. The search area could be expanded once Bluefin 21's current mission is complete.
"If no contacts of interest of are made, Bluefin 21 will continue to examine the areas adjacent to the 10 kilometer radius," the Australian search coordination center said in a statement obtained by NBC News.
Officials also hope to bring in a more powerful underwater drone that can dive 6,000 meters to the seabed. Bluefin 21 can only go 4,500 meters down, the station reported.
In the meantime, the pings are the only credible lead to go on.
"They don't have any other choice," marine scientist Ellen Prager told the station. "Based on the data they have, all indications are that this is the area where the plane went down."
