something hinky about that - an explosive that went off under a trash can isn't going to be heard four miles away in New Paris, or shake a house on S. 19th, 3/4 mile away. An HE grenade wouldn't have those effects, and that would leave more than "remnants of an explosive device placed near or under a trash can."
Maybe a sonic boom - any planefags have eyes on aircraft in that vicinity at that time?