It was 20 years ago today that an Aeromexico DC-9 and a Piper Cherokee collided in mid-air over Cerritos, CA.
I remember August 31, 1986 well. I lived just two miles from the crash site and remember seeing the smoke cloud before I found out what happend. I still live in the area and drive by there almost every day. Of course there is no sign that such a major accident occoured.
This accident led to some major changes with aviation in the U.S. The mode C requirements came about, TCAS was developed, and hopefully safer skies for everyone.