The image of the blown apart engine was posted to Twitter by the Southwest Airlines Pilots' Association.
Southwest released the following additional statement later Saturday:
"When we have an operational event that results in aircraft damage and/or passenger or crew injuries, that can trigger a review or investigation by the National Transportation Safety Board (NTSB). When the NTSB decides to launch an investigation, we give the Board our immediate cooperation so that we are able to properly streamline information and avoid speculation (especially this early).
"If you do not see an update from us, that is because we are working behind-the-scenes with the NTSB to follow this process."
The NTSB has called the incident an "uncontained engine failure" and is investigating.