I thought that even the cabin crew did not know what's burning. There's also the feeling of helplessness -- you know something is wrong but you are not told that something is wrong. The hysteria at the back of the plane could have been alleviated by telling that the situation is under control. When the plane was landing, I could see fire trucks, an ambulance, and police of some sort driving in parallel to the plane to rush in. I only found out about the reason from the news later.