There are still more questions than answers Monday surrounding the Malaysia Airlines flight that went missing this weekend.
The U.S. Navy has now joined international search and rescue teams in the hunt for wreckage of the Boeing 777 passenger jet.
So far, an aircraft spotted a possible lifeboat, and on Sunday, another plane spotted a rectangular object. But ships have recovered nothing.
"We have not found anything that appears to be objects from the aircraft, let alone the aircraft," Datuk Azharuddin Abdul Rahman, director-general of the Department of Civil Aviation, said.
***Could the disappearance of Malaysia Airlines Flight 370 be tied to terrorism? CBN News Correspondent Erick Stakelbeck addressed that question and more, on The 700 Club, March 10.
Experts say the Boeing has an excellent safety record, and they found no problems when the plane was inspected about 10 days ago before the crash.
Even so, the aircraft lost contact with ground controllers somewhere between Malaysia and Vietnam Saturday, with 239 people on board.
Among the missing passengers is American Philip Wood. His family said their faith in Christ is what's holding them together.
"It's devastating," Philip's mother, Sondra Wood, said. "But I know in my heart that Philip's with God and I plan to be there with him because I have a deep faith in my God."
Malaysian authorities said the Boeing's radar suggests the plane, which was en route from Kuala Lampur to Beijing, may have been turning around before it vanished. But there was no mayday call.
"That is a really, really safe place to be, which makes this mystery all that much deeper," retired Col. Stephen Ganyard said.
Meanwhile, yet another mystery is raising questions about possible terrorism.
Malaysian authorities are scouring surveillance footage of two passengers who boarded the flight with stolen passports in an effort to determine their identity.
The FBI and U.S. intelligence agencies are hoping to use super computers to compare the video to images of known terrorists and criminals from around the globe.
"It's not common, but it is not unheard of, either, that stolen passports can be re-purposed and used, mainly for the quality of the passports themselves," Rep. Mike Rogers, R-Mich., said.
Interpol Secretary General Ronald Noble said, "It is clearly of great concern that any passenger was able to board an international flight using a stolen passport listed in Interpol's databases."
Authorities also speculated the stolen passports could be tied to drug smuggling. So far, nothing has been ruled out.