A Boeing plane operated by Southwest Airlines was forced to return to Denver International Airport on Sunday after an engine cowling fell off during takeoff and struck the 737-800’s wing flap.

Southwest Airlines Flight 3695 was heading to William P. Hobby Airport in Houston when the incident happened, according to the Federal Aviation Administration, which is investigating the incident. All passengers and crew on board were safe and the plane was towed to the gate after returning to the airport around 8:15 a.m. local time. Passengers boarded a replacement plane.

Southwest Airlines told KDVR, a local Fox affiliate, that its maintenance team is reviewing the damaged Boeing plane.

The cowling is the removable cover of an airplane engine. Think that big circular metal panel surrounding the engine. They are used to cool the engine and also reduce drag.

Southwest was already having a rough few weeks before this event occurred. Last Thursday, an engine on one of its Boeing 737-800 planes caught fire before taking off from an airport in Texas, and before that, two FAA-scrutinized Southwest flights were disrupted by turbulence.

And of course Boeing doesn’t need anymore bad news, but it keeps getting it. The fallout and intense scrutiny of the planemaker after the Alaska Airlines 737 Max 9 door plug blowout in January isn’t abating, and Boeing is losing a ton of money and consumer confidence in the process.