An attack in London, cruising the Northwest Passage and singing waitressesThe London subway once again comes under attack, and officials suspect its terrorist related. Plus, melting ice means the Northwest Passage is now open to cruise ships. We'll look at the pros and cons. And, sure, nuclear weapons are a big sticking point in any negotiations with the North Koreans. But so too are a group of singing waitresses. Those stories, plus some new music from Kronos Quartet ? today on The World.