Often when a moment dies, and just the ashes remains, you can still feel the fire, then you can tell by the color of the cinder how it was, if they are white, you know it was instantaneous, strong and sudden, if they are black, you see that it was slow, but steady. Afterwards, trying to find the demons of the moment, you can say if there was pain, or happiness, and you can know by the destruction or the creation around the fire, and not because it was just sudden it means it was destructive, but remember, the devil is in the details...