here we go: All the people in the vision were either hit by something, blown out the window, or incinerated. so, no need to cover that.
Tod Waggner-asphyxiation, one of the more suffering ways to die. takes a long time.
Terry Chaney-um, OW? would have hurt, but death would have been almost immediate.
Valerie Lewton-long, suffering death. bloody, severed jugular AND carotid, then a knife shoved through her chest. oh, yeah, and her house exploded. which doesn't really count anyway.
Billy Hitchcock-poor Billy. his brain was among one of the things cut off, so it would have hurt like hell for a fraction of a second, but death came almost immediately.
Carter Horton-WHAM! death may or may not have been immediate.
Alex Browning-death immediate. may or may not have been painless.
Clear Rivers-ouch. but still, quick death.
So, had you been the one suffering Alex's premonition, would you have intervened or not? which way would have spared the suffering?