This is happening here in Cincinnati.. It's leaking from a train tanker. They are saying on the news that one side of the tanker may explode and send the tanker flying like a rocket.
A chemical leaking from a train car has forced evacuations, "shelters-in-place" and left an odor hanging in the air over much of the Cincinnati area.
But, simply smelling the styrene won't harm you, EPA officials told 9News Monday morning.
"You can smell styrene at one part per million. So, you're going to smell it before it has any health effects," said EPA official Heather Lauer.
http://cincinow.com/news/2005/local/08/29/leak.html