The new Park Ave bridge discussed here and the Hancher footbridge are two different structures. I jumped of the footbridge a few times myself. The trick was knowing where to jump. There was a cut in the bank near the boathouse that was deep enough to jump into, but close enough to shore for an easy swim. That's where I jumped.
I don't condone it. Chalk it up to a nineteen year old being stupid. I know a guy who jumped off that bridge as a possible suicide attempt. His friend jumped in to save him and the friend drowned. And who knows what the sediment situation is after the 2008 flood? It is probably a completely different river now.
There was also a drowning incdent in the late 1980's where a student tried to walk across the frozen river in the winter near Mayflower dorm and fell through. Totally senseless tragedy.
I have a feeling the proper authorities will be watching that bridge closely this weekend and violaters will be spending the night in the slammer. It is against the law to jump off any Iowa City Bridge, and doing it upriver from the dam is plain stupid. I'm guilty as charged.