Table 1 List of behaviours observed in CCTV recordings

Sits on the edge of the platform

 Seems to practice jumping

 Leaves objects on the platform

 Often looks down the tunnel

 Walks back and forth between the wall and the yellow line

 Paces on the yellow line

 Stands on the yellow line for a long time

 Strange behaviours

 Anxious or depressive behaviours

 Seems intoxicated

 Stares at the tracks or down the tunnel for a long time

 Psychomotor agitation (repetitive behaviours, nervousness)

 Looks glum (shoulders hunched, head lowered, looks at the ground)