Anyone know the name of an earlier version of this film?

It's driving me nuts - but sometime around the mid/late 80's I saw another version of this film on tv one night (probably, like this one, a remake or copy of the original '73 Romero flick) in which the inhabitants of a small town lose all their inhibitions after a small earthquake disturbs a military weapons dump and the toxin leaks into the local water supply and contaminates the milk of the dairy farm that supplies the community. Eventually the army move in and basically destroy the town and only 2 of the main characters manage to escape. But I can't for the life of me remember the film's name - any of you film buffs able to help me out here?

Thanks :-)