Appears to have been excessive over weight limit collapse.
Found a press release from Ellis County dated January 23, 2012 saying this bridge is scheduled to be replaced.
http://co.ellis.tx.us/archives/37/commissioners%20court%20re...
Looks like it had some help...if you want to call it that!
Great info Anthony. Thanks!
This span appears to exhibit all elements of truss connection. The diagonal eyebars on the outer panels are pin connected at the upper chord/endpost, which are in turn joined together by gusset plates which feature rivets and bolts. The vertical/chord connections have no pins but are also joined with gusset plates riveted and bolted together.
Although many of the bolts appear to have been replaced, it is likely that this little bridge was partially riveted in the shop and then bolted together at the site.
I was about to mention that this bridge was an interesting pinned and riveted hybrid but I noticed that Anthony had already discussed that. This is one of those bridges that gets very interesting when you start looking at fine details.