64 years ago on February 3rd, 1959
American Airlines Flight 320 crashes into the East River on approach to LaGuardia Airport, killing 65 and injuring 8
The plane had taken off from Chicago just before 10pm and was scheduled to arrive at LaGuardia just before midnight. As it descended to land, it crashed into the water ahead of the runway. The investigation following the crash conducted extensive testing of aircraft components and recreations of the flight, but found it difficult to draw a conclusion about why the crew didn't notice the plane was flying too low upon approach. The Civil Aeronautics Board concluded their investigation by saying "The Board concludes there is no one factor so outstanding as to be considered as the probable cause of this accident." Given their testing, the most probable explanation was that a series of smaller instrument miscalibrations and misreadings could have led the crew to think the plane was flying higher than it was, and the night landing over water would not have given them as many visible lights to indicate they were about to hit the water.
This was the first of many crashes for the Lockheed L-188 Electra, which would fail to gain popularity after defects were discovered that caused engine vibrations to resonate and tear the wings off. Even after modifications at Lockheed's expense, public opinion of the plans had been marred and they were relegated to cargo and fire-fighting duties.