DENVER (KDVR) — A preliminary investigation into the plane that caught fire and injured 12 people at the Denver International Airport in March reportedly found many faulty parts on the plane.

The National Transportation Safety Board released the preliminary report on the American Airlines plane, a Boeing 737-823, that took off on March 13 from Colorado Springs Airport to Dallas-Fort Worth International Airport before diverting to DIA and ultimately catching fire.

According to the initial investigation, the report said the plane’s engine experienced “vibrations” during takeoff, but the flight continued. The flight crew reported that one of the engines briefly overheated, and they ultimately decided to land at the nearby Denver airport.

The report found that there was fluid leaking from under the right engine as the plane made its way to the gate. After both engines were shut off, a fire broke out in the area of the right engine.

The report said flight attendants heard passengers yelling “fire” and “smoke” as smoke filled the cabin. The flight attendants tried to contact the flight crew, and passengers got up, wanting to get off the plane. The report said the attendants conducted assessments and then initiated an evacuation.

The fire was reportedly put out within a minute, and people evacuated through the plane doors with an evacuation slide.

Others had to evacuate through vehicles and ladders, as the investigation also found that after the evacuation, a plane door was cracked open and maintenance discovered the escape slide jammed in the door, preventing it from working.

After examining the engine on scene, the report said the right engine nacelle was intact, but distressed, consistent with a ground fire. A fan blade platform was fractured on the engine, a piece of the engine was loose and installed in the wrong direction, and another part was incorrectly fastened, allowing fuel to leak.

The report said the investigation is continuing, with parts of the plane to undergo a more detailed inspection.