What would you do when some one kills a person in front of you ?

I have not seen anyone murder anyone. I did see a terrible accident though, where a young boy chasing his play wheel came in front of slow moving taxi and then I saw the cab wheel drive and crush the boy's head. I felt a sadness that someone so young had to die because of his own carelessness, and the poor taxi driver got into a lot of trouble for no fault of his. The taxi driver did try to save the boy, but had too little time to really react.

i will be shout and cry, and maybe i will be shock and i cannot talk because of afraid.