Ten years ago, an oversized load struck a 'fracture critical' through-truss design bridge on I-5 north of Seattle - causing the bridge to almost immediately collapse (the truck in question managed to make it off the bridge, but a few other vehicles were not so fortunate and fell into the water - fortunately without serious injury to the occupants).
Seems that the bridge had adequate clearance in the left lane, but not in the right lane - the (required) pilot car failed to notify the truck driver, and traffic in the left lane prevented the truck from moving into that lane.