The preliminary report on the I-35W bridge collapse from the National Transportation Safety Board (NTSB) on Tuesday drew a lively discussion on StarTribune.com. Here are a few of the comments.

IT SHOULD HAVE BEEN CAUGHT

Based on the NTSB document and its gusset analysis of the two gussets in question, the bridge was designed with less safety from the beginning. It's curious with the changes and weight added to it over the years, why this was never discovered. As a user of our highways, it makes me very concerned about what else might be dangerous, because something was incorrect.

Mark Schuffenhauer, East Bethel

A COMBINATION OF CAUSES

Let's not forget that this is a preliminary report. The gusset plates will very likely be only one of several combined factors that caused the collapse. Probably any one of the final causes will not explain the collapse, but the combination of them does. If the bridge was initially designed with the miscalculation in size of the gusset plates, I'm not sure how, after the fact that would ever be found, except by a failure.

Brian Uhrig, Brooklyn Center

SOMEBODY SHOULD PAY UP

Back when the bridge was built, we paid for the initial bridge to be inspected. Those inspectors failed to properly validate the blueprints vs. the actual execution of the specifications. Even if it is 40 years, and even if the various companies have been merged, there should be someone's O&E (omissions and errors) insurance on the line. To boot, the bridge was inspected many times. I would think some structural engineer would question the gusset plates being only half as thick as they should be.

Doug Brong, Minneapolis

CIRCUMSTANCES DOOMED BRIDGE

Let me see if I have this straight. We take a bridge designed to hold 250 tons, let it age 40 years with the resultant corrosion and wear, add weight such as thicker concrete and barriers, maintain traffic and then on top of all that we put 50 tons of construction equipment more than originally designed and expect the bridge to hold. What am I missing?

Floyd Cox, Badger, Minn.

SCAPEGOATS DON'T HELP

It is clear that there are only two factors leading to the collapse: 1) poor design and/or construction, and 2) poor maintenance practices by MnDOT. The thing that really has bothered me about this from the beginning is everyone's intense need to blame someone for this. How about we all spend time fixing the problem (change infrastructure inspection and maintenance procedures) and less time and money calling for heads to roll.

Matthew Kettner, Litchfield