80's movie featured on "The Movie Channel"...... Help needed!!?

This has bugged me long enough......I'm looking to see if anoyone may know the name of a movie played frequently on The Movie Channel in the 80's (guessing somewhere bewteen 80' and 84'). The jist of the movie was a group of friends in high school and one by one they start getting killed by wierd happening. Two of the deaths I rememer being as (1) a hang gliders frame snapping and the guy getting electrocuded in some power lines and (2) a guy on the diving team went to practice at night and when he jumped off the board the lights were turned on and showed that all the pool's water had been drained out.....unfortunately, that's about all that I can remember. Don't know if it's considered a kind of cult clic, but struck me as something like that. Thanks for any closure you can offer! ;-)