Initial claims for unemployment insurance were well below expectations last week, helping to douse caution at the Federal Reserve and elsewhere that the labor market is in danger.First-time filings for the week ending Sept. 20 totaled a seasonally adjusted 218,000, down 14,000 from the prior week's upwardly revised figure and significantly less than the Dow Jones consensus estimate for 235,000, the Labor Department reported Thursday.Continuing claims, which run a week behind, were little changed, falling 2, ...