After a United Airlines flight from San Francisco landed in Oregon, a missing panel on the Boeing 737-800 was discovered during a post-flight inspection. The plane, carrying 139 passengers and six crew members, landed safely without incident. The airport briefly paused operations to check for debris but found none. United stated that no emergency was declared during the flight, and they would conduct a thorough examination and investigation before the plane returns to service. This incident adds to recent concerns about aircraft safety.