28 October 2013
Southwest flight WN-3387 , Boeing 737-300 from Nashville to Baltimore took off from Nashville airport and while was climbing struck a bird to the left engine.The crew stopped the climb at 4000 feet advised the tower and diverted back to Nashville for a safe landing on runway 20R.Engine received minor damage
Nashville airport
http://flightaware.com/live/flight/SWA3387/history/20131028/1135Z/KBNA/KBWI
Source
FAA