The result of a Monday-afternoon CSX derailment of four cars carrying caustic sodium hydroxide in WV. From the linked news article, "The derailment resulted in Monday night’s westbound Capitol Limited returning to Washington, D.C., after it had departed there; the rest of that trip was canceled; last night’s eastbound departure from Chicago was also canceled. Both today’s trains have also been canceled, according to the 'Train Status' function on the Amtrak website." The derailment occurred near tiny Magnolia, WV, on the MD border, which appears to be about halfway between the Martinsburg and Cumberland stops on the Limited. As with many such disruptions, good luck figuring this out from Amtrak's website, versus visiting the Site Formerly Known as Twitter, or SFKT.
https://www.trains.com/trn/news-reviews/news-wire/csx-derailment-in-west-virginia-leads-to-capitol-limited-cancellations/
https://www.trains.com/trn/news-reviews/news-wire/csx-derailment-in-west-virginia-leads-to-capitol-limited-cancellations/