In the creepy 1974 film, Peter Graves plays a father who goes on a camping trip with his two teenage children (one of whom is played by Kathleen Quinlan).  A sudden earthquake and a solar flare causes the trio to try to return to civilization, where they discover that almost everyone has been reduced to a powdery substance and there are only a few crazed survivors.  They try to make their way back to their home in Malibu, facing danger at every leg of their journey.

(It’s almost a low-budget and far more dramatic version of Night of the Comet.)

Effective despite its made-for-TV origins, Where Have All The People Gone? was obviously mean to serve as a pilot for a television series.  The series didn’t happen but, even with a somewhat open-ended conclusion, the movie still works.