After doing some reading on the brutal situation down in Minnesota right now, I came across this report on 2006 US bridge conditions:
http://www.fhwa.dot.gov/policy/2006cpr/chap3.htm#bridge
Very interesting that 26.7% of all bridges in the States are rated as "Deficient" with 13.1% as "Structurally deficient." Among that 13.1% was the one that went down yesterday.
The numbers are no doubt similar on our side of the border. This came up a bit on here after the unfortunate Quebec bridge collapse a year ago, but it really makes you wonder where our bridges would be rated and whether this type of information is made public for specific bridges...
Here's a discussion on this site after the Quebec collapse that touches a bit on the 8th st bridge:
http://www.ebrandon.ca/messagethread.aspx?message_id=28565&cat_id=3
You hate to have paranoia over an extremely extremely rare incident, but these are no doubt the kinds of questions that are running through the heads of many.