08:58 AM EDT, 04/08/2024 (MT Newswires) -- (Updates with Southwest ( LUV ) statement in fourth paragraph)

Boeing ( BA ) and Southwest Airlines ( LUV ) shares were down early Monday after the US aviation regulator launched a probe into an incident where a 737-800 jet operated by the airline suffered a structural failure over the weekend.

A Southwest ( LUV ) flight to Houston on Sunday was forced to return to Denver International airport after crew reported the plane's engine cowling fell off during takeoff and struck its wing flap. The Boeing 737-800 jet was towed to the gate, with no casualties or injuries reported.

The Federal Aviation Administration said it will look into the matter. Shares of Southwest ( LUV ) decreased 1.9% in premarket trading while Boeing ( BA ) fell 1.1%.

In an emailed response to MT Newswires, Boeing ( BA ) referred to Southwest ( LUV ) for additional information about the plane and the company's fleet operations. Southwest ( LUV ) said in an email that the company's maintenance team is reviewing the aircraft. "The investigation is still underway, and we do not have anything additional to add at this time," a spokesperson said. The plane was certified in 2015, according to an FAA public record.

The incident is the latest facing Boeing ( BA ) in recent months. In January, one of the aircraft manufacturer's 737 Max 9 planes operated by Alaska Air (ALK) saw a window and a chunk of fuselage blow out shortly after takeoff, prompting the FAA to ground the model for several weeks and open an investigation.

Alaska Airlines said last week that it received $160 million from Boeing ( BA ) for the financial impact of the grounding of the carrier's 737 Max 9 fleet, and expects additional compensation from the jet maker. In March, the FAA revealed plans to investigate three incidents involving 737 planes being flown domestically by United Airlines (UAL) and American Airlines (AAL).

Boeing ( BA ) made senior leadership changes last month, including the departure of Dave Calhoun as chief executive at the end of this year, as part of attempts to regain its footing. Steve Mollenkopf, who is set to take over from Larry Kellner as board chair at Boeing's ( BA ) upcoming annual shareholders meeting, will lead the company's process to find a new CEO.

The manufacturer also refrained from issuing full-year financial guidance when it reported its fourth-quarter results at the end of January, as it outlined plans to improve the quality of its 737 Max planes.

Price: 181.28, Change: -1.86, Percent Change: -1.02