B737-800
Flight Crew Air Transport Pilot (ATP)
Other / Unknown
Aircraft Equipment Problem Less Severe
General Maintenance Action
Human Factors; Aircraft
After this flight we kept the aircraft and crew for the next flight. While the passengers were boarding; two of the passengers sitting in row 15ABC discovered that the seats were not attached to the aircraft. We contacted maintenance and the seats were reattached. We had apparently flown [previous] flight with the row of seats detached; but in their proper location. I don't know how long the seats had been detached; but looking through the logbook I could not find any maintenance performed on the aircraft which involved those seats or any item which may have needed them to be detached for maintenance.Cause: Maintenance or structural issue.Are the flight crews going to have to start checking the seat attach fittings on preflight?
Boeing 737 Captain reported that passengers discovered a row of seats were not properly attached to the aircraft.