A big plane fell down. This happened last year. A broken part made it fall.
The people who look at planes found this. They looked at the engine. They saw a part was old. This part broke.
One engine fell off the plane. The plane fell after it went up. Three people on the plane died. People on the ground also died.
The plane makers are Boeing. Boeing knew this part could break. They told people to check it. But they did not think it was a big problem.
The part got weak. The old letter did not help. This is important news. We must check planes well.