In 2016 the Tromp family living on a farm near Melbourne, Australia appeared to suffer a group delusion and went on an impromptu family road trip.  The disappeared suddenly, leaving behind, money, vehicles with keys still in the ignition, and many other strange things.  Within a few days all were located.  Some had left the group and tried to make it home, others seemed to exhibit strange paranoid behavior and were hospitalized.  None of them know why they left home or why they suddenly feared for their lives.