three of the four buildings were imprecise and had varying damage radiuses , where anyone that boiled tap water for coffee , tea , or anything else would have less than an hour before falling unconscious : the north philly location had a damage radius of about 50 meters , including the second floor apartments , the pizza shop , and the book store ; the location near china town and the one near walnut and locust had a smaller radius of less than 15 meters , the chemical and water system precise to a select few outlets , most of which either unused or in the target destination ; and the spring garden location had only one source of incoming water , and it strictly went to the target .