The records in the various the FRA/DOT incident databases are definitely not complete but when I was searching through them for some WP stuff, I noticed that the WP reports were cataloged under WP's successor, UP. You might try looking under the Soo or even CP. Where exactly are you looking? I used these resources:
http://ntl1.specialcollection.net/scripts/ws.dll?websearch&site=dot_railroads
http://safetydata.fra.dot.gov/OfficeofSafety/publicsite/Query/incabbr.aspx
One fairly serious incident that I knew occurred had very little information available through the web inquiry so I made a written Freedom of Information Act request to the FRA for anything they had on it. I still didn't get much back but they had a few details that weren't in the web generated report. Somewhere on the site there are instructions for making a FOA request on a particular incident. Hope this helps.
Mike