I had a similar "incident" with the Kato Braodway Limited observation.
The circuit became so hot that it burned a hole in the undercarriage, and that warped so much that the car derailed.
My German dealer told me to email Kato U.S.A. for replacement parts, which I received without further questions. The observation is back in service, but I am cautious now.
I asked on Trainboard but it seemed that only one guy had had a similar problem.