I do feel that instances of people threatening to jump ought to be dealt with in a swift and far less delicate manner. Large inflatable jump mats and a taser would do the job. If a person is intent on suicide they tend to just go and do it. Those who spend hours sat on a bridge parapet with the world at a stop, tend to get off again in the end - having caused abject mayhem of nightmarish proportions first. There's plenty of time for help and sympathy afterwards, but the incident itself should be approached with the intention of a swift resolution, in my personal view.
The danger is that for someone who is on the knife edge between actually doing it and not doing it, the sight of someone setting up inflatable mats or whatever beneath them might be the moment that they decide to do it after all, while they've still got the chance.
How much of a bad place do you have to be in, mentally, to bring part of the country to a halt?
Some people undoubtedly get into these situations with no real intention of actually ending their life, but clearly they've become so desperate and feel so isolated that they think their only hope at getting help is a dramatic statement that will get them noticed.
I feel for the thousands of people that had their journeys delayed by hours yesterday, and yet I feel more for the person for whom things have become so truly unbearable that they would knowingly cause such chaos - something unthinkable to most of us in our normal state.