Air force and civilian investigators Monday examined data in the "black box" of an Austral Airlines DC-9 that crashed in fog while approaching a landing field, killing all 22 people aboard.

The "black box," the airplane's automatic flight recorder, was found in the wreckage by rescue workers Sunday afternoon, hours after the crash, and Argentine Air Force and civilian investigators began studying it to determine the cause of the disaster, military and aviation officials said.Posadas, in Misiones Province, is 750 miles north of Buenos Aires.

An Austral Airlines statement said the 15 passengers and 7 crew members on the morning flight Sunday from Resistencia to Posadas all were killed, making it the nation's worst air disaster in seven years.

The statement said the aircraft was "totally destroyed," but rescue workers reported that some of the passengers and crew were found strapped to their seats.