>> keep the road clear! >> reporter: this latest act of violence in london has caused concern across the world, including with the new york police department, who issued a statement saying they were keeping a close eye on the situation, a situation londoners have become all too familiar with. >> tomorrow will be a normal day in london. and the nato summit is coming up next week, so many nation state departments from nato will be here. policing will probably be raised slightly but i wouldn't foresee any dramatic changes. people will go about their normal business, the way they did today. >> reporter: london bridge remains closed tonight, but cbs news has just learned that the attacker was recently released from prison and had a previous conviction for what's being described as an islamist terror offense. john. >> dickerson: imtiaz tyab in london for us. a powerful new storm is about to take a swipe at a big part country. it's already piling up snow in the west. as it moves east, millions of