That.... was really disturbing. You'd think that someone could have stopped him before it got to the point it did.
Yeh but put yourself in that situation. It's at night, you're on a bus asleep and you're awakened by a man screaming only to find when you look in that direction, a crazed man repeatedly stabbing someone with a large knife, all the while people are panicking and screaming, rushing to get out?
Besides, people did do something about it. A passing truck driver and the bus driver made do with makeshift weapons and a crowd of people prevented the killer from leaving the bus until police arrived. Of course, it's tragic that one man had to die in the way he did, but ultimately, the killer was caught and can be brought to justice, rather than have escaped and on the loose, with all the potential to kill again.