I don't think it is as simple as a single event being the cause of the 1947 Palestine Civil War. There were numerous violent encounters throughout 1947. Moreover, the various events were sometimes linked (as in reprisals) and other times independent acts with their own independent origins.

War was inevitable as the rejection of the United Nations resolution to Partition Palestine into a Palestinian and Jewish state meant that "force of arms" and not negotiation was going to be how the territorial disputes were resolved.