Read the two stories and answer the questions.

TWO GOATS
Version 1

    Once upon a time, there was a goat crossing a bridge. There was a river under the bridge. In the middle of the bridge, the goat met another goat from another direction. Since the bridge was so narrow, there was only space for one goat to pass it.

    'Go back,' said one goat. 'No space for two.'

    'Why should I?' said the other goat. 'You must go back.'

    'You are the one that must go back,' replied the first goat with anger, 'because you are not as strong as me.'

    'No one is stronger than me!' said the second goat.

    'Let's see,' replied the first goat, and he positioned his horns to fight.

    Then they started to attack each other. The narrow bridge swayed vigorously. It was not strong enough to handle the two mad goats. Finally, it broke and both goats fell into the river.
 

TWO GOATS
Version 2

    Once upon a time, there was a goat crossing a bridge. There was a river under the bridge. In the middle of the bridge, the goat met another goat from another direction. Since the bridge was so narrow, there was only space for one goat to pass it.

    'Go back,' said one goat. 'No space for two.'

    'Why should I?' said the other goat. 'You must go back.'

    'You are the one that must go back', replied the first goat with anger, 'because you are not as strong as me.'

    'No one is stronger than me!' said the second goat.

    'Let's see,' replied the first goat, and he positioned his horns to fight.

    'Wait!' said the second goat. 'Both of us shall fall into the river and die of drowning if we fight. What about I lie down and you walk over me?'

    Both agreed. The first goat walked over the wise goat laying down on the bridge. They went their ways without having to fight.

Why did the bridge finally break?