Well I'm awful late to this thread lol
Years ago when I lived up in Syracuse, NY, I lived across the street from a plant that handled chlorine. They had a warning alarm when there was a leak, of which there were two while I lived there. You could smell it and feel it before the alarm ever went off. Everybody knew to go inside and shut the windows. It was harsh on the nose/throat/eyes, but everyone was so used to the chemical plants around there I don't think anybody had any fear of injury.
We're all pretty calm here, just watchful. There's nothing I need to do outside the house tomorrow that can't wait another day to be sure.
We don't have the kind of warning system they had in your area so by the time they warned us, it would be too late.