Air France Official: 'We Can Fear the Worst'

The search continues today for the missing Air France plane that disappeared with 228 people onboard over the Atlantic Ocean Sunday night as it flew from Rio de Janeiro to Paris.

If there are no survivors, as many fear, it would be the world's worst aviation disaster since 2001.

The passengers came from at least 30 different countries including two U.S. citizens, 61 French citizens, 58 Brazilians, 26 Germans, nine Chinese and nine Italians.

Brazilian and French military aircraft are now scouring a vast swath of ocean between Brazil and the African coast for the Airbus A330.

VIDEO: Air France Plane Feared Lost Play

Late last night it emerged that a pilot from Brazil's largest airline, TAM, reported having seen something in the sea while flying over the same area that the Air France Flight 447 was heading.

Air Force spokesman Col. Jorge Amaral told the Agencia Brasil official news service that authorities were investigating the report.

"There is information that the pilot of a TAM aircraft saw several orange points on the ocean while flying over the region," he said.

French military patrol planes from Senegal have joined Brazilian ones in searching this part of the Atlantic but conditions are very tough.

Commander Prazuck told the BBC Radio 4 Today program: "We are trying several patterns of search and hopefully we will find something today.

VIDEO: Air France Flight drops off the radar screen not long after take-off.Play

"But the weather is very bad and visibility is poor. We have to go fast... at the very beginning of the operation if we want to be efficient."

He added it was "very unlikely" that any survivors would be found echoing the word's of his president, Nicolas Sarkozy, who said Monday that he had told family members of passengers to prepare for the worst.

Brazil's president, Luiz Inacio Lula da Silva, expressed hope that "the worst hasn't happened," and said "we have to ask God" to help find survivors.

In France, Sarkozy was not the only government official to strike a somber tone. "We can fear the worst," Dominique Bussereau, France's transportation minister, told Europe-1 radio hours after the crash.

An Air France spokesperson told ABC News that the airline was "without any news from Air France Flight 447 from Rio to Paris with 216 passengers on board and a crew of 12 people ... three pilots and nine flight attendants. Air France is very concerned about the emotions and worries of the families involved."

The flight had been expected to land in Paris 5:15 a.m. ET. after leaving Rio around 6 p.m. Sunday night.

The head of Air France, Pierre Henri Gourgeon, told reporters at a news conference that the plane's last radio contact with Brazilian air control was at 9:30 p.m. ET.

Meanwhile, France's Environment Minister Jean Louis Borloo brushed off rumors of a hijacking, telling reporters that the plane probably suffered an accident of some kind.

Automated Messages Came From Plane Before It Disappeared

Earlier today, an Air France spokesperson told Agence France Presse (AFP) that the plane was probably struck by lightning and suffered an electrical failure as it flew through a storm in the Atlantic, although some aviation experts had their doubts about such a scenario.

Greg Feith, former senior air safety investigator with the National Transportation Safety Board, cautioned that it's too early to assume that's what happened.

"We don't have enough information to really put a storyline together, and it may not be possible to put an accurate storyline together, especially if the flight data recorder and cockpit voice recorder are never recovered," Feith said.

What Air France does know is that 10 automated messages were sent directly from the plane to maintenance at 10:14 p.m. after it experienced turbulence and a thunderstorm, saying the plane had experienced an "electrical short circuit."

"That is certainly something we can thank the modern day technology for," said William Voss, president and CEO of Flight Safety Foundation. "Airlines have to keep very close track of their aircraft for maintenance purposes. So when even routine things go wrong, they get a message right away so there is somebody waiting to fix the airplane."

"It sort of provides us a trail of clues and a trail of communications with this aircraft," he said.

If found, the plane's black boxes would also provide many more clues about what happened. Experts said the black boxes emit signals, although only for a finite period of time, in the water.

Reeves of said planes typically fly at about 35,000-37,000 feet. Storms in the tropics can be as high as 50,000 feet.

"In that part of the tropics, with as high as the thunderstorms are, it can be difficult having to go hundreds and hundreds of miles out of your way in order to just get to the point you're trying to get to," Reeves said.

Voss said, "We are really talking about extreme circumstances here. And so a rainy night out of LaGuardia isn't what we are talking about. We are talking about situations that are very extreme, very severe turbulence is assumed occurred here. And there's not many of us -- not even many pilots that have really experienced severe turbulence. You would know it if you had."

The Brazilian Air Force said in a statement that it was anticipating radio contact with the plane when it was still over northeast Brazil. When it received no radio communication, Brazilian air traffic control contacted air traffic control in Dakar, Senegal. There was no Mayday call and no nearby planes received a call for help on the international emergency frequency.

Air France said the captain of the flight had more than 11,000 hours of flight time, including 1,700 hours on A330/A340.

State Department Confirms Two Americans Were Onboard

Hope is now fading for the passengers and crew of the missing aircraft, which include seven children, a baby, 126 men and 82 women.

Meanwhile, more information about who was on board when the plane disappeared is starting to trickle out from various countries.

U.S. State Department spokesman Robert Wood confirmed today that two Americans were on board and that the U.S. government is in touch with their families. He did not name them.

Air France released the nationalities of passengers, including 61 French, 58 Brazilians and people from nearly 30 countries. All 12 members of the crew on the plane were French, according to airline.

Embassy consular staff are at the airports in both countries to assist concerned loved ones.

The plane's manufacturer, Airbus, released a statement saying it would be "inappropriate for Airbus to enter into any form of speculation into the causes of the accident.

"The concerns and sympathy of the Airbus employees go to the families, friends and loved ones affected by the accident," the statement read.

ABC News' Sonia Gallego, Gabriel O'Rorke, Christophe Schpoliansky, Phoebe Natanson, Samira Parkinson-Smith, Kirit Radia and The Associated Press contributed to this report.