Every time I've got a train recently, I've ended up far too worried about whether I'm going to get to my destination on time after a train cancellation, to notice anyone else seeming distressed.
If my own problems weren't consuming me, meaning I noticed, I probably would intervene, but I'd be very cautious about doing it directly to a male. I certainly wouldn't bring up coffee!
I'd find a member of station staff, or I'd ask a question about the station, while standing at a safe distance
Caution is very necessary. This thread has already touched on different suicide patterns, such as the numbers directed by momentary impulse. Some people are motivated by personal misery, and they really don't want to harm anyone else. Some are motivated by anger. I don't want to be in an arm's length of an angry, impulsive man, because he may pull me on the tracks with him.