I was wrong--they evacuated for a half mile:
Subway sandwiches
Subway has done an outstanding job of promoting itself as the “fresh” and healthy alternative to fast food, and to some extent, these accolades are deserved. Much of the chain’s food has fewer calories, fat and sodium than what you get at McDonald’s and the like. But unless you’re getting a sandwich with nothing but veggies, there’s very little about it that’s “fresh.” Even though Subway bakes its bread inside the stores, it’s definitely not Grandma’s homemade loaf going into those ovens.
The dough is produced in one of 10 large, industrial factories around the country, where it’s loaded up with additives like DATEM (short for diacetyl tartaric acid ester of mono- and diglycerides), sodium stearoyl lactylate, potassium iodate, ascorbic acid and azodicarbonamide. That last one — azodicarbonamide — is known to break down into a carcinogen when heated and is a chemical used in the production of foamed plastics. When a tanker truck carrying this substance overturned on a Chicago highway several years ago, city fire officials had to issue their highest hazmat alert and evacuate everyone up to a half mile downwind. Mmmmm, fresh!