Southwest Jet Causes Two Aborted Landings in San Francisco

Two planes aborted landings at San Francisco International Airport after a Southwest Airlines jet taxied across runways on which the other planes had been cleared to land. The Federal Aviation Administration said the decision to abort the landings was "precautionary" and that the appropriate steps were taken to ensure safe operations. The incident comes after a half-dozen close calls in recent months that are being investigated by safety officials. The FAA is investing $100 million in improvements at 12 airports to reduce the number of "runway incursions."