An Air France plane, an Airbus A330-200 with 228 people onboard, went missing on its way from Brazil to Paris on Sunday after hitting strong turbulence and thunderstorms, according to news reports.
"We are without doubt facing an air catastrophe," Air France-KLM CEO Pierre-Henri Gourgeon said in an Associated Press report. "At this time, the plane's fuel reserves would not permit it to still be in flight."
Air France Flight 447 left Rio de Janeiro on Sunday at 7 p.m. local time (6 p.m. EST) with 216 passengers and 12 crew members.
If all 228 people are dead, the accident would be the deadliest commercial airline disaster since Nov. 12, 2001, when an American Airlines plane crashed in the New York City borough of Queens during a flight to the Dominican Republic, killing 265 people.
Military jets took off from both sides of the Atlantic to search for the Air France plane.
According to AP, Douglas Ferreira Machado, head of investigation for Brazil's Civil Aeronautics Agency, said the plane could have been near the coast of Africa by the time contact was lost, based upon the speed it was traveling.
"It's going to take a long time to carry out this search," he said. "It could be a long, sad story. The black box will be at the bottom of the sea."
Air France said in a statement that the plane sent an automatic message reporting an electrical short-circuit about 15 minutes after flying into turbulence.
Senior French minister Jean-Louis Borloo ruled out the possibility of a hijacking of Air France Flight 447 from Rio de Janeiro to Paris, Reuters reported.
"There was very, very strong turbulence. For now we can't understand what happened," Borloo, the second most senior in the government, said on France Info radio.
The jet's last known location was unclear.
A government source in Brazil said the plane disappeared from Brazilian radars about three to three-and-a-half hours into its flight. That would mean controllers lost track of the plane while it was closer to Brazil than to France, Reuters reported.
Henry Wilson, a Brazil Air Force spokesman, said planes had taken off from the island of Fernando de Noronha off Brazil's northeast coast to look for the Air France jet.
Pilots stay in contact with traffic control across the Atlantic by radioing in their position every 20 to 30 minutes. There is no radar cover because radar can only 'see' along a direct line of sight.
Air France said relatives of people traveling on the flight were being taken care of in a special area of Charles de Gaulle Airport.
Part of the terminal was briefly evacuated because of a suspect package but that turned out to be a false alarm.