malfunctions or pile error. The key to solving the mystery is finding debris and the black boxes. Bob woodruff is in beijing with that part of the story. Reporter: This morning, 40 ships are part of a... See More
malfunctions or pile error. The key to solving the mystery is finding debris and the black boxes. Bob woodruff is in beijing with that part of the story. Reporter: This morning, 40 ships are part of a massive multinational effort to find out what happened to this jet. We. Reporter: This a search effort to look for survivors. Reporter: So far, no signal from the black box of the missing 777 and no sign of the plane. Officials say the plane made no distress call. Military radar suggests the plane might have been turning back to cue W Kuala Lumpur. This morning, authorities confirm that oil slick samples found in the south China sea are not from the aircraft. Meanwhile, anxious family and friends are gathered in this beijing hotel, swarming officials, and bracing themselves for bad news. We believe that the family members should prepare for the worst. Reporter: For the family of 50-year-old American passenger Philip wood, the wait has been agonizing. His father, barely able to speak. Great son. He had a big, big heart. He, uh -- he liblged to travel. Reporter: Wood, an IBM executive based in Asia had just recently returned to Texas, to visit his family, including his two sons, nick and Chris. If he was here, he would comfort me and say don't be sad. I'll never really give up hope. That doesn't mean that I won't act September that he may not come back. Odds are we won't see him again. That's okay. Reporter: This is the hotel where the families have been living. They've been praying and hoping something would be found in the sea. The fact that the oil is not from the plane is really upsetting them. Another one this morning they thought they had found a raft from the plane in the sea. It turns out it was a circular cable reel instead. That's not there either. This is still very much a mystery. Robin?
This transcript has been automatically generated and may not be 100% accurate.