WHAT IF: dick died instead of his parents

i saw this question on a google search but it only had one answer and no one asked it since but it got me curious

how WOULD Bruce react to seeing a kid die right before his eyes in such a tragic manner (if i remember right robin joined during batman's third year so bruce was still not fully developed everything about the legend of batman) how would he be affected as batman (since he would not have robin to brighten his mood for a lack of a better word)

how would zuco be dealt with (sorry if i spelt the name wrong but i mean the guy who sabotaged the ropes)

how would dick's parents react to his death and would they become anti/heroes or vigilantes