(Houston, TX) -- The Federal Aviation Administration is investigating after a Houston-bound Southwest Airlines flight had to return to Denver on Sunday. About half an hour after taking off from Denver International Airport, the Boeing 737-800 made an emergency landing after an engine cowling came loose and damaged part of the right wing. Emergency responders met the passengers on the runway, and the travelers soon boarded another flight that landed in Houston around 2 p.m. There were no injuries reported.