Sometimes I'm not lazy and do some research. This quote from Wikipedia (accuracy?) is about the T&P Station. Assuming the T& P Warehouse was vacated at the same time, this would suggest that building has been an empty shell (except for haunted house and various and sundry other ridiculous uses) for 45 years!
"The railroad vacated the terminal in 1967 when passenger service in Fort Worth ended and the.Department of Housing and Urban Development became the exclusive tenant from the early 1970s until the late 1990s." (my note: after which the Terminal was renovated...)