(CNN) -- Did a retired firefighter fall off an Amtrak train as it sped toward Chicago?
That is what authorities are wondering as they continue their search for Charlie Dowd, 69, who has been missing since Friday.
The retired San Francisco firefighter went missing while traveling to visit family, Amtrak police said.
Dowd spoke to his son by cell phone Thursday night, saying he was just outside of Denver, according to his family.
But when his train arrived in Chicago on Friday, he was not on it. His luggage, cell phone and medication were found in his sleeping car, the family said on a Facebook page they set up to find him.
"It is torture not knowing where he is. Torture," his daughter, Jennifer Dowd, told CNN affiliate KMTV.
Amtrak officials told the family that a door of the train was found ajar and passengers saw him acting disoriented near a door, the daughter said.
Amtrak officials said he could have fallen off the train somewhere between Colorado and Nebraska, Jennifer Dowd told the affiliate.
Family members flew to the area and are searching for him.
Dowd takes medication for high blood pressure and heart disease, his daughter said
The family asks anyone with information to contact Amtrak Police or the family on a Facebook page they set up for him.