Koko and the Tunnel Chuggington : Season 1 Episode 4
TV-Y CBeebies 10m int(0)
Aired: September 22nd, 2008 @ 7:50 AM EST on CBeebies
The trainees are heading for a lesson with Dunbar in the training yard when an underground tunnel catches Koko's eye. She wants to explore it but Vee says she isn't ready yet. When no one is looking, Koko decides she's going to see where that tunnel goes, but ends up coming off the tracks.