The UP stated on their website "this outage
will last up to 30 days". Not 2 weeks.
https://www.up.com/customers/announcements/customernews/generalannouncements/CN2017-28.html
Access to the site is very difficult, much more so
than what they had to deal with when the bridge at
Brazos, Texas, slumped and needed major work.
Unlike at Brazos, there is so way the UP can put a
barge-mounted crane in the river near the bridge.
The river is running much too fast for that --
I think that may be one of the reasons.
It will be very interesting to see how the UP manages to
get this bridge repaired or replaced.
And, no, Amtrak will not detour via the Inside Gateway.
That is not practical for more than a few days. Why?
1. Not enough qualified crews, who must be qualified on
both the territory and to operate passenger trains*.
2. It is “dark territory” -- no signals -- so Maximum
Authorized Speed is only 59 mph, not 79 mph**.
*The BNSF is right now getting more crews qualified on the
Inside Gateway. But these crews will still not be qualified
to operate passenger trains -- AFAIK.
**Info on max speed is as of my late 1981 Amtrak detour
over the Inside Gateway.
This would cause the Starlight to be at least 7 or 8 hours
late -- and that is if nothing else makes it even later.
This, in turn, would put equipment and crews way out of place.