Bus subsitution between Burmingham and New Orleans, per AmtrakAlerts:
Service Alert: Crescent Train 19 departing New York (NYP) on 5/11 will terminate at Birmingham (BHM) due to a freight train derailment north of Picayune (PIC). Alternate bus transportation will be provided for passengers between BHM and New Orleans (NOL).
Funny thing, there's a branch line that connects in Hattiesburg, skipping Picayune and Sidel to the East. The downside is that they'll have to put engines on both ends for the entire trip, because you'll have a few reverse moves to get on the right tracks.