PIERCE COUNTY, Wash. -UPDATE
10:41am : Six fatalities have now been confirmed. Right now all are believed to be passengers on the train.
9:32am : Officials have confirmed at least three fatalities
Emergency crews are on the scene of a passenger train derailment over Interstate 5. An Amtrak train derailed south of Seattle shortly before 8:00am. Authorities say "injuries and casualties" have been reported.
The train derailed on an overpass over I-5 southbound about 40 miles south of Seattle. Officials say that weather conditions won't allow helicopter evacuations. No numbers on injuries or casualties have been released yet.
All southbound lanes of I-5 south of Join Base Lewis-McChord are closed and motorists are being advised to avoid the area.