[E. Pluribus Unum]

Not being a pilot, how do these type collisions happen?......................

When pilots decide to buzz their homes to say "hi."

Seriously.

Sounds like two pilots were doing it at once.

[central_va]

Mid air collisions flying VFR are rare but the do happen. Planes have large blind spots. If two aircraft are using the same air space each should know the other’s altitude. Radios are your friend.