Complex sentence: On October 10,1997, Austral Flight 2553 left this airport for Buenos Aires and crashed one hour later in Fray Bentos, Uruguay, killing 75 (all crew and passengers), this being the worst accident from a commercial airline for Argentina and Uruguay.
Split into simpler sentences: On October 10,1997, Austral Flight 2553 left the airport for Buenos Aires but crashed one hour later in Fray Bentos, Uruguay, killing 75 (all crew and passengers). This was the worst accident from a commercial airline for Argentina and Uruguay.