From one of the news sources:
People with questions about the status of loved ones on the train can call Amtrak at (800) 523-9101.Praying that your family is safe.
Yes I called the number yesterday. They told me that they were already put on another train to go to their next destination. They were supposed to arrive yesterday around 2 pm. As of last night they still didn’t arrive. So we’re not sure what’s going on. I haven’t spoke to anybody today, so someone else in the family may have gotten in touch with them. Thanks for the prayers. I’m sure they are okay. Everything is probably just chaotic right now because the officials are still trying to locate some 28 missing ticket holders.