It took 10 months. In fact, since my first day working at the Standard-Examiner I reported on a Union Pacific train derailment in Weber Canyon. After coming back to the office, I promptly put in a (Freedom of Information Act) FOIA request for the details of what happened in the accident.
In June, I got a response letter telling me it could take 6-9 months for the investigation to be complete.
10 months later, I finally got the report.
Here is the follow up story. along with the original video from the first story I did.