derailed at Rheinfelden last night
https://www.20min.ch/schweiz/basel/story/SBB-Cargo-entgleist--Bergung-dauert-an-30160899

Judging from Google Maps, the locomotive seems to have been moving westbound and to have gone off the end of a stub truck northeast of the intersection of Koosfeldstrasse and Breitmattweg. One explanation could be that the locomotive passed a signal at danger and then went through the turnout that keeps trains off the main line in such a case. But someone reading this may have more information.

George