The dashes should be inserted between "bridge" and "an", and the second dash should be between "gorge" and "while".
Without the hyphens, the sentence is a bit too long and over-connected. There needs to be some sort of pause to describe the bridge the jumper is jumping off of.
:)
We will go to the store as soon as my dad gets back from work
C the introduction of the novel
B. Here is some empty parking spaces.
