Southwest Airlines flight 3006, a scheduled international passenger flight from William P. Hobby Airport (HOU), Houston, Texas, to Los Cabos International Airport (SJD), San Jose del Cabo, Mexico, experienced a right engine failure resulting in an air turnback. During the turnback, a burning odor was reported in the cabin and an evacuation was commanded after landing. During the evacuation, one flight attendant (FA) sustained a serious injury. According to the flight crew, they were on day two, leg two, of a three-day line experience rotation. The first officer (FO), pilot flying, was returning from leave and the captain (CA) was a line check airman for the company. During the preflight, the flight crew discussed the automatic terminal information service (ATIS) reporting windshear and planned for a precautionary takeoff profile. The flight crew briefed the engine out procedures and the takeoff profile for runway 22. The taxi and takeoff were normal. During climb out, the flight crew observed the right engine exhaust gas temperature (EGT) indication momentarily increase into the red overtemp range, then decrease. The flight crew then heard a “popping” noise and observed the right engine N1 indication decrease to approximately 50%. The CA declared an emergency with air traffic control (ATC) and initiated the Engine Fire, Severe Damage or Separation quick reference checklist (QRC) and the quick reference handbook (QRH) procedures. The FO continued as the pilot flying and coordinated vectors for a return to HOU. The “A” FA contacted the cockpit to inform them of a burning odor in the cabin. The CA informed the FAs that they had an engine malfunction and were returning to HOU. The CA then made a public announcement informing the passengers that they would be landing in 20 minutes. After completing all appropriate checklists, the CA assumed control of the aircraft, and the FO transitioned to the pilot monitoring. The approach and landing were uneventful. ATC requested that the flight crew exit the runway at the end and coordinate with airport rescue firefighting (ARFF). After clearing the runway and stopping, the CA contacted the FA’s and was informed that there was still a strong burning odor in the cabin. At that time, the CA elected to initiate an evacuation of the airplane. The CA informed ARFF of the decision and the FO began the QRH for an evacuation. The flight crew completed the QRH procedure, including left engine shutdown and FLAP 40 extension, and the CA commanded an evacuation via the left side of the aircraft. The FO evacuated the aircraft to assist with the evacuation while the CA remained onboard until all passengers had evacuated. The CA observed passengers re-entering the aircraft from the overwing exits and then utilizing the door slides. After all passengers and flight attendants had evacuated the aircraft, the CA conducted a final walkthrough and evacuated the aircraft. On the ground, the CA learned that ARFF personnel had directed passengers back into the aircraft due to concerns of injuries sliding off the wing. According to the “B” FA, seated in the aft galley, during takeoff there was a loud noise and followed by a burning odor. As the aircraft continued to climb the odor intensity decreased and they inspected the area and were unable to identify a source. The B FA contacted the A FA and informed them of the odor. The CA made an announcement that they had experienced an engine failure, and they would be landing in approximately 20 minutes. After landing and stopping, the CA called the FAs and asked if the odor still existed, to which the B FA replied that they still smelled a burning odor. After the evacuation, the B FA reported an injury to their ankle. They were diagnosed with a hairline fracture.