The Federal Aviation Administration said on Sunday that it would launch an investigation after the engine cowling of a Southwest Airlines flight ripped apart while taking off from Denver International Airport. The Houston-bound plane, a Boeing 737-800, turned around and landed safely in Denver around 8:15 a.m. after the cowling, or cover, fell off and struck the wing flap. The flight reached an altitude of 10,000 feet before its emergency landing, according to CNN. Southwest said that the flight’s 135 passengers were transferred to a different aircraft and transported on to Texas approximately three hours behind schedule. “We apologize for the inconvenience of their delay, but place our highest priority on ultimate safety for our customers and employees,” the airlines said in a statement that promised it would review the aircraft. Reached for comment by CNBC, a Boeing representative pointed back to Southwest’s statement. The mishap marks the second such incident for Southwest this week, with the FAA also probing a reported engine fire that broke out on a plane in Lubbock, Texas ahead of takeoff.