@GreenSkyOverMe @GreenSkyOverMe It is "fietsen" (riding bike) indeed and sounds like whistle the fist part. It is quite common to go cycle in Holland, but "ga toch fietsen" means also go away.
So is says "the train is broken, go cycle".
Mss stands for "mischien" meaning "maybe"
It is a very funny kind of childish line, and not the common way the railway company communicates with the travelers.