American investigators have settled on three primary theories to explain the disappearance of Malaysia Airlines Flight 370, a senior U.S. official told ABC News tonight.
The leading theories are:
1. Pilot suicide or other human action;
2. Fire or catastrophic mechanical malfunction;
With terrorism all but ruled out, however, investigators still are leaning toward the vanishing of the passenger jet with 239 travelers and crew aboard as "a deliberate act," the official said.
"That's pretty much what everyone thinks," the senior U.S. official, who receives frequent updates on the investigation, told ABC News.
Get All the Latest Updates on the Vanished Malaysia Airlines Plane
The Obama administration has been cautious all along in the sparse public statements they have made over the past two weeks, beyond pledging to assist the Malaysian government.
Asked about lithium batteries known to be aboard MH370, the official said the amount and weight of the potentially flammable cargo "has been classified" secret by investigators but said it was "comparable to the Dubai jet," referring to UPS Flight 6, which crashed in the United Arab Emirates in late 2010.
Still, the focus of the probe, as ABC's Brian Ross was told a week ago by another senior official, remains primarily on what happened inside the cockpit rather than in the cargo hold, noting that the aircraft is believed to have flown more than seven hours after taking off from Kuala Lumpur on March 7.
Finding out what happened to the jet and how it vanished seemingly into thin air must be determined by the U.S. in order to ensure it isn't repeated or becomes a national security vulnerability, the official added.
The official spoke after the Chinese government released a satellite image showing a new object floating in the water today, another lead for search crews trying to find the missing plane.
China's State Administration for Science, Technology and Industry for National Defense released the photo of the object, which is reportedly 74 feet long and 43 feet wide. It was spotted about noon Tuesday in the southern Indian Ocean, about 75 miles southwest of the region where two objects released by Australia were previously seen.
The news of the object interrupted a press conference Malaysian officials held, as Malaysia's Acting Transport Minister Hishammuddin Hussein was given a piece of paper containing details about the object. He concluded the press conference early as reporters peppered him with questions about the development.
Before receiving the note, Hishammuddin told reporters that China, India, Pakistan, Myanmar, Laos and Kyrgyzstan hadn't found anything related to the plane in the northern search corridor.
Malaysia Airlines Flight 370 disappeared on March 8.
Search crews again came up empty during the third day of the search in the desolate southern Indian Ocean. There was no reports of any sign of the missing plane or the two objects spotted by satellite in the area six days ago.
The search area covered Saturday, an area of 36,000 square kilometers, included the area where the new object was spotted by Chinese satellites but the object wasn't found, according to the Australian Maritime Safety Authority.