Bangkok CNN  —  Anxious loved ones waited outside a twisted mass of metal and concrete in the heart of Thailand’s capital on Saturday as rescuers searched for dozens of missing workers and the city confronted the aftermath of a rare and powerful earthquake that set skyscrapers swaying and rattled millions of residents. Friday’s 7.7-magnitude quake struck hundreds of miles away in impoverished Myanmar, but was strong enough to send shock waves through the forest of high-rise condominiums,