The US baggage number is 1-800-371-4771. I don't know if you can get past the robots and speak with a real person there, however.
If you are still in Europe, the number there is 00800 24567890.
I only know these things because all 4 of our family's bags were lost or delayed on a return flight from BMA 3 days ago, so have the paperwork in front of me.