No need to apologize, it has been an accident.
Leo smiled at Deneb, it is the less thing he can do when someone is being polite, after that he approached the train in order to help.
The wheel? If you need it I can help you, but still...
Leo began to examine the broken zone, he just wants to take a closer look.
I´m curious, what exactly happened? the wheel just went away? or did you hit something?
Tico: maybe the wheel wants to be free.
I don´t think so... anyways I´m just asking because I want to know it, since is not normal for a wheel leave by his own, maybe a screw failed, and that is a signal the train needs a maintenance.