In the aftermath of this week's tragedy in Minneapolis, a lot of attention is focused on the nation's infrastructure.  As is all too often the case, it takes a catostrophic event to shed light and bring attention to important -- often life and death -- issues.  In this case, most of the attention is focused on the 600,000 bridges in the U.S.  But our attention can't be limited only to bridges.  The state of infrastruct…