Bit of Retroactive Recognition - Carol, Dale and Andrea are the lady who goes to find her children, Dan Miller (the older man who is the first to warn everybody about the creatures in the mist) and Amanda Dunfries (the schoolteacher) respectively.
King first thought up this story after having actually witnessed a storm that bad while on vacation. He went to the grocery store for some more emergency supplies, and while he was standing the (very long) checkout line, he randomly pictured something like a pterodactyl flying over all the customers.
A lot of key parts were omitted from the original script:
The failed experiment that summoned the mist.
Brent's rationalization on why he doesn't believe David, the mechanics or Ollie
Carmodie's followers are already in the process of sacrificing people