Captain Jeremy Nielsen

Coming up.

Until you stand up next to one, it's tough to grasp how big those really are.

It's a single-point failure bridge, much like the Francis Scott Key Bridge.

So if you hit that support tower, the top of the ship hits the underside of the bridge, that whole bridge is coming down.

The largest vessels that we see, 1,200-foot container ships, until you stand up next to one, it's tough to grasp how big those really are.

So our safety margins have decreased dramatically.

The problem certainly isn't limited to the Columbia.

We're highly trained.

We are very, very good pilots.

But our skill only goes so far.

We need infrastructure improvements, technology to make sure this river stays safe.