You are correct that it's a small risk. But the risks of losing 100 people in a bus accident or to the building collapsing are rather small compared to even a plane crash..
Anecdotally, I was in the organisation of a conf who lost a significant portion of our visitors to a tram collision a few years back. Not really of course, they were just half an hour late :P
Anecdotally, I was in the organisation of a conf who lost a significant portion of our visitors to a tram collision a few years back. Not really of course, they were just half an hour late :P